The mission was hard specially when we don't know where it is. After going out of Zero's portal, they found Eleven. With her Dark Venom form.

    Eleven kept fighting and fighting, but the unknown enemy were sucked into her. Changing her into a darkness monster.

   "Eleven..?" Zero called out. Then Eleven turned around half of her is her venom form that change into more darker and more evil looking. The other half is her. Normal her.

  "Run..RUN!" Eleven shouted. And her normal her start to crack. The darker her was taking control of her. Little by little.

  "ELEVEN-SENSEI! CONTROL YOURSELF" Grigio shouted. "ELEVEN-SENSEI!?" Grigio shouted half shocked to see Eleven face cracking even more.

  "I-.. Run.. Run away..NOW!" Eleven demanded.  "Please, just at least outside the border of the planet.. Please.." Eleven pleaded. And so the other ultra's go.

  The siblings who is Zero and Eleven, had a device, which can make them talk to each other, but the furthes away that they can talk is 20 kilometers only.

  "Hey, Zero." "Eleven, what's wrong? Please, talk.." Zero replied into the device. "Can you stay like 20 meters away from the border? Just a few seconds." Eleven said.

  "Yeah.. Sure."

With Zero replies, Eleven started cracking more and more. She uses one of her powers, [Flaming hands] which make her hands flaming and so does her feet.

  She started to wrap herself with her flaming arms. She started to crack more after doing that. But this time. The dark half of her crack to.

  She started crack and cracking. Again and again. Until the heat of her own body exploded the half of the planet she standing in.

  Her timer started beating rapidly. Zero then came.
With his friends.

  "ELEVEN" "SENSEI" All of them shouted. They all kneeing in front of her laying body..

  "I think I'm dying.. Take care of my kids if I did die, Zero.." She started. "Don't even said that! Your fine, just transform into your light form.. It'll slow the timer.." Zero said.

  And so she did.. It doesn't slow her timer at all. Zero made a portal and they all went in. But it's too late. At the middle of teleporting, Eleven say. "I'm sorry. But I think it's too late.. Everything's become a blur.." She said.

  "N-no, Eleven!" Rosso said. "You HAVE to live! What about your family!?" Blue then said. "Sensei! What about our family on earth?!" Grigio said.

  Eleven looked at them. Then Zero. "I'm sorry.." she said. Then her timer goes off, the lights don't shine anymore. And so does her eyes. They aren't lit anymore.. She's dead.. Dead..

Zero looked at her dead body before arrived at his planet. The ultra's seem to understand the poses of them. And the condition of Eleven. And Eleven we're kept in a certain box. The box contain another device.

  The ultras desperately trying to revive her. But they still don't know. If Ultra Eleven would be alive again.

    Zero blaming himself.
Eleven's kids kept visiting the certain box.
  Eleven's spouse kept crying.
        Grigio and her brother kept trying to comfort Zero and Seven.

    But the high rank ultras still trying to revive Eleven. None of them knows if it will happen.