kakuzu is good if u put him as 1st. u can play around with the combo with konan. she can give u a 20 combo if u can breakthrough her chase.that is the cheapest option . u can summon the Fox as well.

What would I use to get the 20 combo?

Try using Azure(With poison passive),Jinpachi(His passive provide edo dei double atk standard),edo dei and kkz .

But to be honest,edo dei and egf kkz does not fit well tgt(Until recently they release the kkz skill breakthrough which is insane).

Demon Fox summon instead of slug. Problem solved. Of course you are then relying on Kakuzu to always start the combo. If you don't want to deal with that then use KoH or chameleon.