Gelos is from Underswap!180 and, well, his brother, Blueberry, wasn't the best to him to say the least.

Through a series of events I won't give away, he ends up leaving his AU to travel with Pazuzu - who is on a very dangerous mission you could say.

Gelos isn't strong physically, he's not much of a fighter, instead he is a healer. A self taught one but still a good one.

Before he left with Pazuzu, he didn't wear his glasses more often than not because of certain reasons. Without them, he might as well be blind. He has a good sense of awareness without his glasses, great at guessing and dodging even if everything is a huge blur. After his fall with Pazuzu, when he goes through his partial order, he wears his glasses without fear.