

With a group it's much easier to manage the spiderants/rats, he's less focused on one target and it's much easier to open the valves since you can assign one person to always do that. He can be soloed, but of course a group really does help. No shields spawn with immunity to both elements (unless there's a unique/legendary I'm unfamiliar with) Pyro Pete isn't actually a big problem except for the loooong fight and the DOT effects, just keep moving and he'll never hit you with anything else. The fight is mostly about managing the non-pete enemies to make sure you can wash off the DOT, can get a second wind but so you don't get swarmed.

Try to always leave a spiderant around to kill for a second wind (and so you can open the valve without washing in more enemies each time). In short, use Shock or normal damage, slag him, use the Bee, release Spiderants not rats.
Pete the invincible full#
So you'll still slowly lose health and never have full shields.

Immunity doesn't mean you don't take the DOT damage either, it just significantly reduces it.Some people suggest Fire/Corrosion immunity shields to limit his DOT effect, but later on in the fight he'll be doing both Fire and Corrode DOT every Nova anyway, so unless you've got a fire/corrode immune Bee I wouldn't bother with it trying to immunize yourself.Try and open them every once in a while for health/ammo since he takes a LOT of bullets to kill. There are respawning ammo crates around the arena for a reason.If you can stand leaving a spiderant alive and kite him around like Pete you should be able to water yourself down immediately after each nova no problem. If one spiderant/rat is alive when you turn the valve, no more will spawn.The spiderants are far far easier to deal with than the Rats Open the south (I think) valve as it has Spiderants.This will limit the leveling up of the mobs from the valves Consider letting two DOT effects stack before opening the valves.They increase in level by 3 each time they're spawned, ending in 66 I think. Opening the valves spawns a group of Rats or Spiderants.The DOT effect is weak but it limits your shield's abilities (read: it removes The Bee's effect) walk through the water to remove the DOT effect. The water valves open and let you remove the long lasting DOT effects from his novas.His DOT (damage over time) effects never wear off over time, so don't wait for them to go away.Slag guns are far less useful in solo play through. If you have Slag grenades or a skill that slags, use it. Pete can be slagged like a normal enemy for a normal duration.Aside from the Damage over Time effects, it's extremely easy to dodge Pete's attack if you simply walk backwards and shoot at him. The Bee really really helps, especially during the start.Non-elemental works fine against him too I think. Shock works just fine against him and makes removing the shield a breeze. Shock does normal damage against flesh/armor, so 1.0x not 0.8x.
