After You Helping Hand Choice Band Explosion Lickilicky is what you are looking for.
You'll need:
- Lopunny with the move After You (-> makes Lickilicky move right after Lopunny, which is fast)
- any pokemon with Helping Hand to boost you
edit: you might need Fire Punch on Lopunny to take down Steel types resisting Explosion
PS: actually this is not really a good method after all lol you can try with a Ghost type immune to your own Explosion and a pokemon with Sturdy on the other side, so you are covered.
PS2: another strong combination would be Choice Band Earthquake + Choice Specs Discharge
You'll need:
- Lopunny with the move After You (-> makes Lickilicky move right after Lopunny, which is fast)
- any pokemon with Helping Hand to boost you
edit: you might need Fire Punch on Lopunny to take down Steel types resisting Explosion
PS: actually this is not really a good method after all lol you can try with a Ghost type immune to your own Explosion and a pokemon with Sturdy on the other side, so you are covered.
PS2: another strong combination would be Choice Band Earthquake + Choice Specs Discharge