Risk of Rain UO Engineer

I've mentioned before that the Engineer seems to be kinda the stock class for unlocking Origin, and there's good reason for that. Every single one of his skills can be used to dish out damage from safety; fire Tri-nades down cliff edges, lob Thermal Harpoons from literally anywhere, drop a Turret as you flee so it distracts the enemy or drop one after hopping off a rope for a split-second to dish out good damage for a surprisingly long time, drop Mines in anticipation of spawns and clear out, or drop them after hopping off a rope for a split-second as a direct attack on those below you. He's also fairly resistant to Distortion, and gets disproportionate benefit from the cooldown reduction; Thermal Harpoon is the closest thing he has to an essential skill (And in most situations he just needs to get a little creative to work around the lack), and the cooldown reduction absolutely applies to Mines and Turrets. Being able to drop all your Mines and both your Turrets and expect to get them back quicker than normal is quite useful!

His only real weaknesses for such a run are that he's sort of susceptible to Spite Bombs, in that he has no evasion moves or mobility moves, and that he actually doesn't scale well to swarms, particularly since Spirit means enemies will effortlessly end up triggering a Bounding Mine without actually being hit by it as their HP drops and their speed rises. And the Spite Bomb point is highly misleading since the Engineer is the best class in the game at dishing out damage from distant, safe locations; he doesn't need to perform dodge rolls or the like when he can just be lobbing Thermal Harpoons through solid rock, or dish out damage without ever leaving the safety of a rope, or otherwise avoid ever being in a position for a Spite Bomb to kill him. It still crops up when, for example, dealing with hordes of Evolved Lemurians, but in most cases it's not a flaw at all.

That said, the Engineer has a bit of a rough start, as it's fairly easy to eg lob a Thermal Harpoon, only for a Golem to spawn on top of you right after you've started firing and end up instantly clapped to death. Bounding Mines and Turrets don't occupy the Engineer, but his other moves have enough time commitment that until you've got a few Soldier's Syringes it's easy to make minor missteps and be unable to correct them before they kill you. (This is a noticeable part of why I think Acrid is probably better, especially paired with his superior ability to scale to swarms)

As an aside, doing all these UO runs has gotten me convinced that Elder Lemurians do percentile damage on their Spite Bombs, which would be pretty insane if so given how many they release on death. They do percentile damage on their regular attack, and Spite Bomb damage is derived from a unit's basic damage value. It's not a stretch, and it's astounding how often Elder Lemurians have instantly ended a run attempt because just a few Spite Bombs managed to kill me after I killed one Elder Lemurian. In any event, it's noteworthy because in runs where Spite is not on Elder Lemurians tend to not be that big of a deal. The fact that they do percentile damage means they're slow to kill you -they're only really dangerous if you let them stack, or if you're careless because you've gotten to some insane HP value other enemies struggle to do real damage to. Outside those situations, they're normally a lot less dangerous than other enemies... except when Spite is on, when they're suddenly one of the worst possible enemies to deal with. In the context of an UO run where Kin is also on, that makes for another example of insanely swingy luck, where a run going super well, managing to get over a thousand HP by the time it reaches the Temple of the Elders without specifically grinding, is still in a position to die instantly if Elder Lemurians end up being the spawn. It's really frustrating, especially because the Temple of the Elders' other enemy possibilities are honestly mostly way easier. It'd be one thing if the Temple of the Elders was just always a difficult hurdle in an UO run, but this wild swinginess is just frustrating.