Thank you to everyone who commented! Your responses were really helpful!
(and just a quick FYI, the dashes are for time changes while spaces between paragraphs are for POV changes)

Losing himself in the currents of his magic, for he trusted it to know where it was needed, Harry was pulled into a meditative state. Unbeknownst to him, the path his magic weaved as it moved up Bumblebee's arm left radiant trails of blue light in their wake, enthralling his audience.

Ratchet watched the healing process with intense scrutiny as scratches and scapes that had adorned Bee's outer armor smoothed over when the blue energy escaping from the human swept over them. Harry did seem to be able to heal Cybertronians, though it was not something Ratchet couldn't do with the correct tools and time. Unfortunately, the medic had neither here on Earth.
Wherever the blue light went, bents, scratches, and scrapes seemed to heal perfectly, though the paint that once adorned those damaged areas was gone.
After the light had swept Bumblebee's entire body, Ratchet was surprised to see the blue energy glow brighter and condense on the spot in which he had attempted to bring back the young scout's voice box. The surgery had not been his biggest failure, but it haunted him all the same. Every time the camaro had to speak through his radio to get his point across to humans or use his com channels to talk to the team in person, Ratchet felt a small bolt twist in his spark. If his failure could be fixed...
Just as the hopeful idea crossed his processor, the strange blue light faded and Bumblebee's optics jumped open. The scout sat up immediately, and his optics darted around before they locked onto Ratchet's. "Doc, where's the human? Is he alright?"
The medical officer felt his shoulderplates slump just a little as the com channel fed into his processor. Of course the young mech's voice box wasn't healed. There was no logical way a human could heal important Cybertronian physiology.
Just then, Harry used that odd ability of his to fly into the air and hover next to Ratchet's helm, looking at the scout in curiosity.
"Aaasxzshjshhh!"
Ratchet's receiver stood straight up in shock. Quickly replaying the sound in his processor, the medic couldn't believe his audio receptors. That sounded an awful lot like...
"Hey Bumblebee, thanks for saving me. How are you feeling?" The human flew in close to the scout's face.
Bee tried to lean backwards with what sounded like a staticky 'huh' escaping his opened mouthplates.
"Harry, if you'd back up a moment please," Ratchet requested, feeling like his spark was about to overload. The medic barely registered that the human had flown back over to his side as he scanned Bee with his strongest scanners. He could go a couple days without energon; this was too important not to check.
"Ratchet, what's going on? Did you give me some bad energon? I'm seeing and hearing weird things..."
The orange and white Autobot could not keep his optics from widening as he quickly read through all of the scans. Not only was Bumblebee's voice box back up to one hundred percent working capacity, but his energon stores were completely full as well.
Stomping down on his awe, Ratchet stared at the young mech with his strictest look. "Bumblebee," he said, "I need you to try saying your name for me."
The black and yellow bot narrowed his optics. "Bumbhhuxjlbeiee." The mech's optics opened so wide Ratchet was almost afraid he'd strain his optic coverings, but there was no stopping the young Autobot now. "Booumbalybiee. Buoombleaybaaaae. Bumblebaiey! Bumbbhlllebee! Bumblebee! Bumblebee! Bumblebee!"
Bee got up off the table and jumped around, slapping Bulkhead and Wheeljack on their backs and shoulderplates before he tackled Ratchet, crowing his name as he crushed the older medic underneath him and in between his arms.
Ratchet, once he started, couldn't stop laughing.. Despite the mech now laying on top of him, an incredibly heavy weight seemed to fall off of his shoulderplates, making the older mech feel lighter then he had in ages.

Harry watched as Bulkhead and Wheeljack joined in on the robot pile in quiet joy. This was the part he loved most about being an Arcane Healer. Seeing how delighted his patients were after terrible ailments they were told would never heal, were brought back to one hundred percent. If he wasn't wrong, Bumblebee would only need to practice using his vocal chords for a few more days before his brain would pick up on the old signals and bring his speech back to what it had been previously.
It was as the wizard turned to leave that more thunderous footsteps approached their location. The gaggle on the floor was too distracted to notice, but Harry recognized the chain connecting him to another growing shorter. The Autobot that needed his help the most was coming.

-

"We don't know where he is, and, until we do, I'm going to have to ask you and your team to keep your guards up and your volume down. I, for one, don't want to involve any other civilians in this mess."
Optimus Prime looked down at the human attempting to passive-aggressively scold him. Robert Epps was many things, but a forgetful man, Optimus thought not. The Technical Sergeant had forgiven him and his team for their blatant disregard for secrecy with Sam Witwicky and Mikaela Banes, but he did not lose a chance to remind the leader of his displeasure with the arrangement.
"Of course," Optimus replied. "I will give your request to my fellow Autobots."
Epps opened his small mouth to say more, but large crashes coming from the medical room shook the ground and catwalk the two beings were standing on. "Now, Optimus," the man settled for instead.
The Prime nodded his helm before turning and making his way to the med room. Two subsequent crashes put Optimus on alert, but there were no sounds of fighting that the large mech could pick up with his audio receptors.
Walking into the room, Optimus quickly saw why.
Bumblebee, Bulkhead, and Wheeljack were all piled on top of Ratchet, who, surprisingly, was laughing instead of menacingly swinging his wrench, as he did whenever annoyed. It was a weapon Optimus commonly saw whenever he was in the room.
The laughing pile of Autobots quickly stopped when he stepped into the room. Optimus felt his spark dim just a little. He enjoyed being the leader of their group, but it was not pleasant to have to be 'cool, calm, and collected', as the humans said, for his soldiers at every moment in time. He never would regret receiving the honor of being a Prime, but sometimes, in his spark, he despaired. Had he never touched the Matrix of Leadership, maybe he could be enjoying what little time they all had off from battling with the Decepticons to loosen his wiring a bit. Instead, his internal fans were always working and a caution from his stress sensors was ever present in the corner of his vision. The Prime knew, even with his more resilient build, that he wouldn't be able to last much longer under these conditions, but surely...
"Bumblebee!"
Optimus' processor jerked to a halt mid-thought. Turning his optics to his young scout, the leader watched, dumbfounded, as the yellow and black robot untangled himself from the bodies of Autobots and raced over to latch onto his arm, a smile prominent on his mouthplates as he shouted again. "Bumblebee!"
The young scout suddenly furrowed his opticplates before he mumbled, "Orpthimoose... Orptimuse... Optimus." Turning brilliantly shining optics onto the leader- who was still unable to make his processor move on from its shock- he shouted, "Optimus!"
Bumblebee did a little jig, still holding onto Optimus' limp arm, where he sang, "Bumblebee! Optimus! Vuozz beeack!"
Finally, after resetting his processor, the Autobot leader was able to pat the mech on his shoulderplate with his free arm.
"Indeed," he intoned, his own mouthplates quirking up into a stiff smile at the exuberant display. "I am glad you have your voice back, Bumblebee. It has been too long."
Turning to look at the mechs who had climbed up from the floor and wiped off their armor, the Prime nodded to his medical officer. "You did an excellent job, old friend. I thank Primus every day that you decided to join us."
Everyone turned to look away from Optimus and towards Ratchet as the medic loudly reset his voice box. "While that is a wonderful sentiment, Optimus, it's a bit undeserved."
The huge Autobot only had time to raise an opticplate in question before Ratchet gestured to a previously-unnoticed human floating in the air over by the medical table. "This man, Harry Potter, is the one who healed him."
Shocked on more than one account, the leader didn't even think to move when Harry flew closer. Two processor freezes in such a short time under loads of stress- Optimus was in danger of short-circuiting.
However, as soon as the human touched his main faceplate, Optimus could think again. It was as if a cloud had lifted from his processor. The large mech blinked his optics a few times before he turned a kind smile onto the human who had backed up in the air a few feet.
"Thank you for your help then, Harry Potter. I am forever in your debt."
The human nonchalantly waved his hand. "Think nothing of it," he dismissed. "Bumblebee here is not the only one I have to help though. Why are all of you in trouble in one form or another?"
Optimus, confused despite his perfectly working processor, looked to Ratchet for answers. Their medical officer would know of anything that could put them in danger if there was truly something off.
The leader watched as his old friend blinked for a klik in shock before turning blue optics onto Harry.
"You healed Optimus just now, didn't you?" He questioned. Healed him? Optimus wondered what exactly they were talking about. The human had touched his faceplate, nothing more.
Harry nodded in response despite the Prime's doubts. "I believe his brain was, sort of, stuck, for lack of a better word. There is a great deal I need to help him with, but all I did there was fix a newer problem."
Optimus stared at the human in awed and curious confusion. How had he known that the leader's processor was struggling? The bespectacled man seemed very odd for a human.
"Ratchet, would you mind explaining what you mean?" Optimus requested. The longer he stayed silent in this conversation, the more lost he felt.
"A blue light just came from Harry's hand and surrounded your helm, Optimus," Bulkhead commented, his mouthplates set in a wide grin. The Autobot leader was glad to see the green and black mech in higher spirits.
"Yes," Wheeljack confirmed, "there was a brilliant blue light, and it sunk into your helm. Your optics are brighter now than they were when you entered the med room as well. I wonder exactly what that energy is..."
Optimus felt his jaw clench lightly at the gleam in his bomb specialist's optics. The mech was brilliant at being a 'mad scientist', but he had been descending into his madness a bit more without his experiments. It seemed he had developed another obsession, except this one was unacceptable in the leader's optics. He would need to talk to the red and silver mech after this about his experiments.
"Yes," Ratchet finally answered, sending menacing glares to both the mechs beside him. "Harry here seems to be able to heal both humans and Autobots with an unidentified blue light. It healed several of Bumblebee's scrapes before it recovered his voice box. If you wouldn't mind, I would like to see what he did for you."
Optimus said nothing as he stepped towards his medical officer. To be able to heal such old and difficult damages... Such a healer would be very beneficial to have on side if there was ever an emergency Ratchet couldn't take care of.
Lost in thought, Optimus stood perfectly still as everyone else watched Ratchet scan their leader.

It was only a few moments before Ratchet had received the information from his scans. The medic felt his optics fly wide as he turned to stare at Harry in awe.
"You..." he trailed off, still staring at the floating human.
"Ratchet?" Optimus questioned.
"He- I- No, that's- that's not possible," Ratchet stammered before he went back to his scans, pulling up the ones he took of Bumblebee and comparing the two.
After a few more moments, Ratchet turned to Harry and clarified, "You said we all had something a bit off with us?"
Harry nodded again.
Ratchet covered his spark with a servo as he continued to stare at a miracle. "By the Allspark..," he whispered in awe.

Harry shifted nervously under the medic's intense stare. What did he do now? Did he cure something he shouldn't have? But his powers told him it was important to heal the leader. The need was so strong that he wouldn't have been able to fight the pull of his powers even if he wanted to. The wizard was just lucky it didn't require him to cure more than the robot's brain. Harry had only just recovered from healing the hopefully-about-to-defect Decepticon. He'd rather officially get out of this place before the military personnel got wind of him meeting the Autobots. He could always come back later undetected.
"Ratchet, is there a problem?" Optimus asked again. Harry broke out of his thoughts and turned his attention back to the orange and white medic.
"No," Ratchet shook his head. Then he started to laugh again. "It's actually quite the opposite!" he exclaimed.
Bulkhead placed a hand on the laughing mech's shoulder with concern furrowing his metal brows. "Are you okay, Ratchet?"
Harry watched in curiosity as the medic looked at the burly mech with a confused frown before he blinked and his smile widened. "Oh, yes, I apologize. I'm perfectly fine. It's just- I feel so much better now, actually."
"Ratchet," Optimus said again, his voice laced with a mix of concern and authority, "what is the matter?"
The older mech chuckled before he said, "It's more like what's not the matter." Ratchet gestured towards Harry again as he said, "Harry can sense when we have low energon. He can also refill our stores."
Every single little movement in the med room suddenly stopped, and Harry watched nervously as all the Autobots turned as one to look at him with wide eyes and awe-struck faces.