Antman x The Atom + Story

Quarks Origins by MoonKnightFan101:
Ryan Lang started out as a young but very intelligent thief. His younger sister suffered a cognital heart condition, Ryan sought the aid of a surgeon but being desperate to help his younger sister, Ryan decided to return to thievery. Breaking into the house of his idol, Professor Raymond "Ray" Pym. Ryan stole the shrinking Pym lens, a powerful artifact obtained from star material. The whole time, Professor Ray was curiosly oberving him and when Ryan got out of the house, the professor followed him home while shrunken down. After he saw Ryan trying to help his sister by modifying the Pym Lens into shrinking him, professor Ray stepped in and gave Ryan a hand. Surprised, Ryan asked if the professor was following him and Ray answered yes, to see what was the motif behind Ryan stealing his Pym Lens. The attempt at curing Ryan's sister was successful, following which, Professor Ray welcomed Ryan to Ivy University seeing how intelligent and talented Ryan was. After the inevitable graduation, Ryan took up the mantle of "Quark", Professor Rays old superhero persona.

Both characters belong to Marvel and DC respectively.