Walking Wake looks threatening as hell and I look forward to seeing the carnage it can and will wreak, but let's take a closer look at Iron Leaves!

The first things you notice about Iron Leaves's stat spread are its nice 130 base Attack, its chunky special bulk, and its actually solid base 104 Speed. In fact, that special bulk starts to remind me of Hoopa-U: it's actually enough to tank a powerful super-effective special attack once! This is good because it shares that biting 4x weakness to U-turn and lower physical bulk with Hoopa-U.
If you're using Iron Leaves instead of Meowscarada, it's because of that bulk (along with easier access to Swords Dance).
Iron Leaves @ Choice Scarf
Ability: Quark Drive
Tera Type: Dark
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Leaf Blade
- Close Combat
- Night Slash
- Psyblade
Scarf Iron Leaves outspeeds Scarf Garchomp and can leverage its bulk to revenge things
despite its nasty weakness profile:

Vs. Scarf Gholdengo
252 Atk Iron Leaves Night Slash vs. 0 HP / 0 Def Gholdengo: 160-190 (50.7 - 60.3%) -- guaranteed 2HKO
252 SpA Gholdengo Shadow Ball vs. 4 HP / 0 SpD Iron Leaves: 252-296 (78.2 - 91.9%) -- guaranteed 2HKO

Vs. Great Tusk
252 Atk Iron Leaves Leaf Blade vs. 0 HP / 4 Def Great Tusk: 234-276 (63 - 74.3%) -- guaranteed 2HKO
252 Atk Great Tusk Knock Off (97.5 BP) vs. 4 HP / 0 Def Iron Leaves: 238-280 (73.9 - 86.9%) -- guaranteed 2HKO

Vs. Iron Treads
252 Atk Iron Leaves Close Combat vs. 0 HP / 0 Def Iron Treads: 226-266 (70.4 - 82.8%) -- guaranteed 2HKO
252 Atk Iron Leaves Leaf Blade vs. 0 HP / 0 Def Iron Treads: 127-150 (39.5 - 46.7%) -- guaranteed 3HKO
252 Atk Iron Treads Ice Spinner vs. -1 4 HP / 0 Def Iron Leaves: 262-310 (81.3 - 96.2%) -- guaranteed 2HKO
252 Atk Iron Treads Knock Off (97.5 BP) vs. -1 4 HP / 0 Def Iron Leaves: 318-376 (98.7 - 116.7%) -- 93.8% chance to OHKO

Vs. Specs Greninja
252 Atk Iron Leaves Leaf Blade vs. 0 HP / 0 Def Greninja: 408-482 (143.1 - 169.1%) -- guaranteed OHKO
252 Atk Iron Leaves Close Combat vs. 0 HP / 0 Def Greninja: 362-428 (127 - 150.1%) -- guaranteed OHKO

Vs. Booster Energy Iron Valiant
252 Atk Iron Leaves Psyblade vs. 0 HP / 0 Def Iron Valiant: 288-338 (99.6 - 116.9%) -- 93.8% chance to OHKO
252 SpA Iron Valiant Shadow Ball vs. 4 HP / 0 SpD Iron Leaves: 156-184 (48.4 - 57.1%) -- 91.4% chance to 2HKO
252 SpA Iron Valiant Moonblast vs. 4 HP / 0 SpD Iron Leaves: 138-163 (42.8 - 50.6%) -- 2% chance to 2HKO

Vs. Rotom-W
252 Atk Iron Leaves Leaf Blade vs. 252 HP / 4 Def Rotom-Wash: 278-330 (91.4 - 108.5%) -- 50% chance to OHKO (guaranteed OHKO after Stealth Rock)
252 Atk Iron Leaves Leaf Blade vs. 252 HP / 252+ Def Rotom-Wash: 204-240 (67.1 - 78.9%) -- guaranteed 2HKO after Leftovers recovery
252 Atk burned Iron Leaves Leaf Blade vs. 252 HP / 252+ Def Rotom-Wash: 102-120 (33.5 - 39.4%) -- 14.1% chance to 3HKO after Leftovers recovery

Vs. Specs Dragapult
(OK, this one's not so good)
252 Atk Iron Leaves Night Slash vs. 0 HP / 0 Def Dragapult: 194-230 (61.1 - 72.5%) -- guaranteed 2HKO
252 Atk Tera Dark Iron Leaves Night Slash vs. 0 HP / 0 Def Dragapult: 290-344 (91.4 - 108.5%) -- 50% chance to OHKO (guaranteed OHKO after Stealth Rock)
252 SpA Choice Specs Dragapult Shadow Ball vs. 4 HP / 0 SpD Iron Leaves: 306-362 (95 - 112.4%) -- 68.8% chance to OHKO
0- Atk Dragapult U-turn vs. 4 HP / 0 Def Iron Leaves: 236-280 (73.2 - 86.9%) -- guaranteed 2HKO
252 SpA Choice Specs Dragapult Draco Meteor vs. 4 HP / 0 SpD Iron Leaves: 249-294 (77.3 - 91.3%) -- guaranteed 2HKO
This leaves Swords Dance, Taunt, Substitute, and friends for wallbreaker sets.
Iron Leaves @ Life Orb
Ability: Quark Drive
Tera Type: Dark
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Taunt / Swords Dance
- Leaf Blade
- Close Combat / Wild Charge / Psyblade
- Night Slash

If you can actually catch Skeledirge trying to Will-O-Wisp Iron Leaves, a Taunt set can break through Skeledirge, its mightiest Unaware wall and normally one of its best checks:
252 Atk Life Orb Iron Leaves Night Slash vs. 248 HP / 0 Def Skeledirge: 200-237 (48.6 - 57.6%) -- 94.9% chance to 2HKO
8 SpA Skeledirge Torch Song vs. 4 HP / 0 SpD Iron Leaves: 176-210 (54.6 - 65.2%) -- guaranteed 2HKO

Gholdengo is immune to Taunt, forcing Iron Leaves to use Swords Dance instead to try to break it. Unfortunately, Iron Leaves has trouble cracking fully defensive Gholdengo without Terastallizing. Meta shifts may make Gholdengo not want to go full Bold max. Defense, though:
252 Atk Life Orb Iron Leaves Night Slash vs. 252 HP / 96 Def Gholdengo: 190-224 (50.2 - 59.2%) -- 74.2% chance to 2HKO after Leftovers recovery
252 Atk Life Orb Iron Leaves Night Slash vs. 252 HP / 252+ Def Gholdengo: 148-177 (39.1 - 46.8%) -- guaranteed 3HKO after Leftovers recovery
+2 252 Atk Life Orb Iron Leaves Night Slash vs. 252 HP / 96 Def Gholdengo: 374-442 (98.9 - 116.9%) -- 93.8% chance to OHKO
+2 252 Atk Life Orb Iron Leaves Night Slash vs. 252 HP / 252+ Def Gholdengo: 296-351 (78.3 - 92.8%) -- guaranteed 2HKO after Leftovers recovery
0 SpA Gholdengo Hex (130 BP) vs. 4 HP / 0 SpD Iron Leaves: 336-396 (104.3 - 122.9%) -- guaranteed OHKO
0 SpA Gholdengo Hex (130 BP) vs. 4 HP / 0 SpD Tera Dark Iron Leaves: 84-99 (26 - 30.7%) -- guaranteed 4HKO
0 SpA Gholdengo Make It Rain vs. 4 HP / 0 SpD Iron Leaves: 154-183 (47.8 - 56.8%) -- 89.1% chance to 2HKO
0 SpA Gholdengo Make It Rain over 2 turns vs. 4 HP / 0 SpD Iron Leaves: 257-306 (79.8 - 95%) -- not a KO
252 Atk Life Orb Tera Dark Iron Leaves Night Slash vs. 252 HP / 252+ Def Gholdengo: 221-265 (58.4 - 70.1%) -- guaranteed 2HKO after Leftovers recovery
+2 252 Atk Life Orb Tera Dark Iron Leaves Night Slash vs. 252 HP / 252+ Def Gholdengo: 445-525 (117.7 - 138.8%) -- guaranteed OHKO
+2 252 Atk Life Orb Tera Dark Iron Leaves Night Slash vs. 252 HP / 252+ Def Tera Flying Gholdengo: 222-263 (58.7 - 69.5%) -- guaranteed 2HKO after Leftovers recovery

So the Taunt set cracks Dondozo easily.
252 Atk Life Orb Iron Leaves Leaf Blade vs. 252 HP / 252+ Def Dondozo: 252-299 (50 - 59.3%) -- 77% chance to 2HKO after Leftovers recovery
0 Atk Dondozo Wave Crash vs. 4 HP / 0 Def Iron Leaves: 72-85 (22.3 - 26.3%) -- 16.8% chance to 4HKO
0 Atk Dondozo Avalanche (120 BP) vs. 4 HP / 0 Def Iron Leaves: 192-228 (59.6 - 70.8%) -- guaranteed 2HKO

Clodsire is easily broken period:
252 Atk Life Orb Iron Leaves Leaf Blade vs. 248 HP / 8 Def Clodsire: 286-337 (61.7 - 72.7%) -- guaranteed 2HKO after Leftovers recovery
0 Atk Clodsire Poison Jab vs. 4 HP / 0 Def Iron Leaves: 152-180 (47.2 - 55.9%) -- 74.6% chance to 2HKO

Unfortunately, Iron Leaves needs Wild Charge to even try to get past Corviknight without Terastallizing:
252 Atk Life Orb Iron Leaves Close Combat vs. 248 HP / 252+ Def Corviknight: 118-140 (29.5 - 35%) -- guaranteed 4HKO after Leftovers recovery
+2 252 Atk Life Orb Iron Leaves Close Combat vs. 248 HP / 252+ Def Corviknight: 237-279 (59.3 - 69.9%) -- guaranteed 2HKO after Leftovers recovery
252 Atk Life Orb Iron Leaves Wild Charge vs. 248 HP / 252+ Def Corviknight: 179-213 (44.8 - 53.3%) -- 1.2% chance to 2HKO after Leftovers recovery
+2 252 Atk Life Orb Iron Leaves Wild Charge vs. 248 HP / 252+ Def Corviknight: 356-421 (89.2 - 105.5%) -- 31.3% chance to OHKO
0 Atk Corviknight Brave Bird vs. 4 HP / 0 Def Iron Leaves: 254-302 (78.8 - 93.7%) -- guaranteed 2HKO
0 Atk Corviknight U-turn vs. 4 HP / 0 Def Iron Leaves: 204-240 (63.3 - 74.5%) -- guaranteed 2HKO

Toxapex is easier to crack with Taunt than Swords Dance thanks to the threat of Haze. Iron Leaves might need both Taunt and Swords Dance or to use Psyblade to crack Chilling Water Toxapex, though:
252 Atk Life Orb Iron Leaves Leaf Blade vs. 252 HP / 192+ Def Toxapex: 107-126 (35.1 - 41.4%) -- 70.6% chance to 3HKO after Leftovers recovery
252 Atk Life Orb Iron Leaves Wild Charge vs. 252 HP / 192+ Def Toxapex: 143-169 (47 - 55.5%) -- 16.4% chance to 2HKO after Leftovers recovery (11.1 - 13.1% recoil damage)
252 Atk Life Orb Iron Leaves Psyblade vs. 252 HP / 192+ Def Toxapex: 190-226 (62.5 - 74.3%) -- guaranteed 2HKO after Leftovers recovery
0 SpA Toxapex Sludge Bomb vs. 4 HP / 0 SpD Iron Leaves: 110-132 (34.1 - 40.9%) -- guaranteed 3HKO
0 SpA Toxapex Chilling Water vs. 4 HP / 0 SpD Iron Leaves: 15-18 (4.6 - 5.5%) -- possibly the worst move ever

Garganacl is also easier to crack with Taunt than Swords Dance:
252 Atk Life Orb Iron Leaves Leaf Blade vs. 252 HP / 228+ Def Garganacl: 234-276 (57.9 - 68.3%) -- guaranteed 2HKO after Leftovers recovery
252 Atk Life Orb Iron Leaves Leaf Blade vs. 252 HP / 228+ Def Tera Fairy Garganacl: 117-138 (28.9 - 34.1%) -- 98.9% chance to 4HKO after Leftovers recovery
252 Atk Life Orb Iron Leaves Wild Charge vs. 252 HP / 228+ Def Tera Flying Garganacl: 156-185 (38.6 - 45.7%) -- guaranteed 3HKO after Leftovers recovery
0 Atk Garganacl Salt Cure vs. 4 HP / 0 Def Iron Leaves: 49-58 (15.2 - 18%) -- 97.4% chance to 4HKO after Salt Cure