Minimal effort with maximum profit
First off, Sableye needs to run Foul Play.Don't use this:
View attachment 1537
Sableye @ Leftovers
EVs: 252 HP / 120 Def / 136 Sp. Def
- Night Shade
Why it's bad:
Now, before you call me ridiculous for pointing out a Pokemon with Prankster, hear me out. Sure, it has an amazing ability that allows it to wall effectively. However, with Sableye's awful stats and predictability, it is very ineffective. 50/75/65 is awful for a Pokemon that is meant to stall. Will-O-Wisp breaks physical sweepers, but the fire type is commonly used in UU (Victini, Darmanitan...), so Sableye is vulnerable to these. Also, it cannot break special sweepers, which can easily OHKO or 2HKO Sableye. Taunt may stop your opponent from putting up Stealth Rocks/Toxic, but there are Pokemon that do a better job (Crobat, Ambipom...), so using Sableye for Taunt isn't really your best choice. Recover is a good HP restoring move, but since a lot of attacks do over 50% to Sableye, it is an ineffective Pokemon to use.
I have no complaint against Night Shade.
Use this instead:
View attachment 1538
Arcanine @ Leftovers
EVs: 252 HP / 116 Def / 140 Sp. Def
Bold / Impish / Careful / Calm Nature
- Morning Sun
- Flamethrower / Flame Charge
- Toxic / Protect
Why it's better:
Arcanine is a much better wall than Sableye for many reasons. The first reason is the stat spread of 90/80/80, which is much better than Sableye's stats. The second reason is it breaks physical walls upon switching in thanks to Intimidate. Thirdly, the moves. Will-O-Wisp breaks physical walls even further by burning them. Morning Sun allows Arcanine to recover his health by 50%, or 75% if you're using a sun team, making it even better. Flamethrower deals some very nice damage, while Flame Charge will speed up your wall, out-speeding scarf-less sweepers after one or two of these. Lastly, Toxic allows it to deal damage against other fire types, and Protect allows it to stall out burn damage and leftovers recovery.
The last, and best thing about this set, is that it is uncommon and difficult to counter.
0 Atk Sableye Foul Play vs. 0 HP / 0 Def Darmanitan: 265-313 (75.49 - 89.17%) -- guaranteed OHKO after Stealth Rock
0 Atk Sableye Foul Play vs. 0 HP / 0 Def Victini: 260-308 (76.24 - 90.32%) -- guaranteed OHKO after Stealth Rock
0 Atk Sableye Foul Play vs. 68 HP / 0 Def Chandelure: 126-150 (45.32 - 53.95%) -- guaranteed 2HKO after Stealth Rock
There is no reason to use Night Shade when Foul Play is so awesome and manhandles incoming Fire-types. Secondly, Speed really matters in Pokemon. The fact that Sableye has priority may seem trivial, but the ability to heal and cripple Pokemon before they can attack is amazing and makes Sableye very viable. Thirdly, defensive Arcanine is not that great. Your wall is weak to Stealth Rock in a metagame where spinning is difficult, and while offensive Pokemon can get away with it, defensive can't. Its also not at all difficult to counter, a ton of Pokemon in UU can safely switch in and force it out. Ironically, this Arcanine actually will lose against all non Scarf Fire types.
-1 252 Atk Life Orb Sheer Force Darmanitan Rock Slide vs. 248 HP / 116+ Def Arcanine: 190-224 (49.6 - 58.48%) -- 64.06% chance to 2HKO
0 SpA Arcanine Flamethrower vs. 0 HP / 4 SpD Darmanitan: 82-97 (23.36 - 27.63%) -- possible 4HKO
252 SpA Life Orb Victini Psychic vs. 248 HP / 140+ SpD Arcanine: 148-175 (38.64 - 45.69%) -- 91.02% chance to 2HKO after Stealth Rock
252+ SpA Life Orb Chandelure Shadow Ball vs. 248 HP / 140+ SpD Arcanine: 187-222 (48.82 - 57.96%) -- 59.77% chance to 2HKO
I mean it just doesn't do much.