So, I came up with this cool combo and decided to test it. It's a long combo, but perfect for Baton-Pass chains. Btw, I tested this, and it works quite well, although it takes up half a team. Only required things are listed here.
So, here's how it works:
Umbreon @ Leftovers
252 HP/252 Def
Do anything, but make it a TRAP PASSER.
Carnivine @ Leftovers
252 Spd
Leech Seed
Baton Pass
Ingrain
Set up a subseed, then pass to Electrode
Electrode @ Leftovers
0 HP/252 Spd
0 HP Ivs
Substitute
Thunderbolt
Thunderwave
Electorde uses his speed to keep the Sub, and 1/8 of thier health absorbed from Leech seed heals almost 1/4 of his health. That, + Leftovers, + Ingrain will help a LOT. So, he has an infinite Leech seed and an unbreakable sub. Fun.
I know, this is a long and fragile combo. But still, it can work.
So, here's how it works:

Umbreon @ Leftovers
252 HP/252 Def
Do anything, but make it a TRAP PASSER.

Carnivine @ Leftovers
252 Spd
Leech Seed
Baton Pass
Ingrain
Set up a subseed, then pass to Electrode

Electrode @ Leftovers
0 HP/252 Spd
0 HP Ivs
Substitute
Thunderbolt
Thunderwave
Electorde uses his speed to keep the Sub, and 1/8 of thier health absorbed from Leech seed heals almost 1/4 of his health. That, + Leftovers, + Ingrain will help a LOT. So, he has an infinite Leech seed and an unbreakable sub. Fun.
I know, this is a long and fragile combo. But still, it can work.