Risk of Rain UO Acrid

Acrid is honestly probably one of the best classes to try to unlock Origin with -it only took me this one try to succeed with him, and while there was certainly an element of luck involved, he's just really well-suited to it in general. So long as Festering Wounds isn't locked by Distortion, he's actually one of the better classes at killing single big targets (eg Greater Wisps), and no matter what skills are locked he's quite good at dealing with mobs since Epidemic and Caustic Sludge both scale to enemy count and affect potentially a huge area. -Caustic Sludge in particular can be kept continuously active in an area anytime it's not locked thanks to Distortion reducing the cooldown. He's also got unusually high armor and high health regeneration, both of which extend his durability in a manner Glass doesn't directly hurt, and he's able to dish out most of his damage while keeping focused on being on the move. Where eg the Commando has to juggle avoiding enemy attacks and Spite Bombs and try to arrange a place to fire from all at the same time, a player running Acrid can pay minimal attention to their offense while still actually killing things.

The fact that the majority of Acrid's damage is delayed, not requiring his ongoing presence, and half his attacks outright penetrate through walls also just considerably simplifies the logistics of avoiding being killed by Spite Bombs. Lay down Caustic Sludge, flee to cover, and voila, the enemies are dying after you've gotten to safety. Or you can use Neurotoxin and/or Epidemic to get enemies right through walls so Spite Bombs have no chance of reaching you at all. These factors make it easier for Acrid to avoid things getting out of control in the first place -instead of ending up with a cluster of enemies that are difficult to approach due to all the Overloading and Volatile enemies, and which are difficult to wear down due to the Leeching enemies, you're steadily killing them as they arrive and problem situations like that just don't really get an opportunity to get going.

The one scenario that can be a bit of a nuisance for Acrid is that Overloading big nasties early on can be tedious to actually kill since you can't afford to try to close with them to use Festering Wounds and can't safely loop through them with Caustic Sludge. Distortion locking Festering Wounds can also be inconvenient if you're dealing with something like Greater Wisps, but that's a problem that will usually eventually solve itself -whereas Overloading enemies never stop being Overloading.