"It was a series of three. I read it as a kid.

It was really messed up, though. The first book cover had a really graphic picture of a fish person (I think there were two) and the third book had a cover of a mutant dude with burnt skin and a bicycle helmet fused to his head. And the second book just had a picture of an open water tank in the middle of a desert with a bunch of other water tanks.

Also there was a guy in a wheelchair and the main character I think goes blind at the end of the second book... because he spends the whole book in a cave and when he goes outside he looks at the sun.

And in the first book he’s just a kid living in his parents’ house and then by the third book his wheelchair friend has his legs CUT OFF so he can walk on his hands faster, his other friend has like 80% of her body completely burnt, the main guy is blind, and they are all in the desert fighting a war against mutants with bicycles. It escalates quickly."