Ahh, time for this tightly tangled-up sonofabitch to shine :D
Anyways, I think I might have mentioned this set at least twice out of the ~35 other posts I have made during this lifetime, buuuut here it goes again.
Yellow Cheese, you almost stole the set I'm about to post, buuuuut not quite! :)
TANGLED CLUSTERFUCK @ Life Orb
Ability: Regenerator
EVs: 252 HP, 4 Atk, 252 SpA
Nature: Quiet
-Leaf Storm
-Focus Blast
-Knock Off
-Sludge Bomb/Power Whip
Tangrowth is usually known for being tanky with its 100/125/50 defenses whether it'd be a physical or a mixed one with Assault Vest, but this set instead utilizes its 100/110 Offensive stats, which is really neat for a defensive tank. It can effectively utilize a Life Orb, as Regenerator can patch up the Life Orb recoil.
Leaf Storm is Tangrowth's go-to move as it severely dents anything that doesn't resist it, Focus Blast is a great coverage move that hits Steels + Hydreigon on the switch, Knock Off does what Knock Off does best, while still doing relevant damage, and Sludge Bomb hits some other fellow Grass-types and Florges for super-effective damage. Power Whip, however, can be used over Sludge Bomb as it is a strong Physical STAB that is still capable of cleanly 2HKOing the bulky waters and any Florges that don't run Defense investment.
Proof of 2HKOs (all after Leftover recovery):
4 Atk Life Orb Tangrowth Power Whip vs. 252 HP / 252+ Def Suicune: 221-265 (54.7 - 65.5%)
4 Atk Life Orb Tangrowth Power Whip vs. 252 HP / 252+ Def Slowbro: 229-273 (58.1 - 69.2%)
4 Atk Life Orb Tangrowth Power Whip vs. 252 HP / 0 Def Florges: 231-273 (64.1 - 75.8%)