I finally took this guy off hold.
Out of the four who were corrupted by Nightmare, Epic is the one who acts most like his original self. He's still a jokester, but his pranks have became far more sadistic and he lost the ability to feel any remorse.
He's been the most fun of the Corrupted to write. His chapters with Blueberror and Core are very hectic.
The way I like to describe evil Epic is "Jigsaw (Saw) if he made more 'deez nuts' jokes".
He really embraced the science/tech side of his personality and spends most of his time building traps and weapons from scrap metal.
He implemented a device into his fingerless gloves that can shoot poison, which can cause burns and temporary blindness.
Epic still uses his rubber chicken a lot, but he also loves, loves explosives and the weapons he makes. I draw him with grenades a lot. It just happened.
Epic lives in Epictale despite it being one of the first AUs to be infected and destroyed. He lives in an abandoned robotics factory where he used to work. He turned his old office into his bedroom.
Near the beginning of the apocalypse, Core Frisk sent out a troop to capture Epic and try and cure him. One of the people who went after him was Epic's brother. Only half of the team returned alive. Epictale Papyrus was not one of them. His armor and dust was recovered by Core with his head melted from an acid Epic was trying to make.
Epic was the one Core tried slapping really hard to see if that would snap him out of Nightmare's hypnosis.
Most of Core's experiments and tests on the Corrupted were attempted through Epic. The reason is he is the only one who stays in place without being too dangerous. Blue is somewhat of a wanderer, Dream is highly unstable, and Cross is always close to Nightmare.
Epic is really into video games like Fortnite and Call of Duty and more importantly, bullying the children on those games. No plot relevance, I just thought the idea was really funny.
If you found the AO3 version of the story, you may have noticed the tag "Epic deals drugs to a child". Without spoilers, the child is Core and the drugs in question were made by Dream that he got his hands on.
Epic gets his own song in episode 5 (?) of the series. It's Wouldn't You Like from EPIC. Ironic.
Design notes! Epic wasn't too hard to design. He did originally have a backpack and a sash of grenades (like Ink's), but that was removed because it made him too complicated to draw. The backpack also would've caused too much weight for a character who's meant to be agile and lurk around. That's what's the camo jacket is for. His camo patches are hard enough to draw, I didn't want to add more details.
Epic has extra scars on his face from repetitiously getting into accidents and fights. It took him a long time to finally use proper protection.