Honestly, I'm not too in love with this pokemon. It's certainly cool, and its ability, and it does have a nice little support movepool, but it's just too frail. Against pure stall/defensive teams that are hella passive, then, sure being able to toxic everything behind a sub and encore and disable and all that is great, but against offensive teams, then what? You taunt something, you get hit, you die. You Nasty Plot, you get hit, you die. As a pure life orb sweeper, there are better mons to do the job. Weavile is faster, hits harder, and has more coverage options, and is even bulkier, for what it's worth.
The best use might be as a life orb sweeper that has that utility of being able to toxic anything. Toxic/Venoshock is a nice combo. Or for a nasty plot set, going with encore as a way of being like anti-setup on things you outspeed while also setting up yourself. Something like NP/Encore/Sludge Bomb/Fireblast. Really, it's a bit of a shame. Barring the 4x weakness to ground, Poison/Fire is a solid solid defensive typing, but even with those defenses, you're hardly going to be taking even resisted hits very well. Corrosion is a good ability, but just not suited for this pokemon, beyond just being a nice little tool in your kit.
In lower tiers, it should do pretty well, I imagine, but even then not amazing power and those awful defenses will hold it back