Planeswalker Infinite Ultimate Combo
3 cards, in addition to the walker(s) you want to be hitting the ultimate of:


Tezzeret the Seeker
The Chain Veil
Everflowing Chalice


Chalice needs at least 4 counters, to pay for the veil, tezzeret +1 untaps both chalice and veil allowing infinite uses of veil which resets both tezzeret and the other walker(s), letting you rebuild the + abilities on those walkers until they ultimate again and again.