Obviously your going to want to run counter doublers like
Doubling Season and
Deepglow Skate.
Doubling Season makes infinite tokens with Jace the
Cunning Castaway. Another fun combo is to double the counters on
Tamiyo the Moon Sage and
Tamiyo, Field Researcher, then if you ult them both you can cast an instant or sorcery from your hand infinite times most likely winning the game. One more combo is Kaya, ghost assasin cast when you have
Oath of teferi out. It allows her to drain your opponents for two and you gain two, then you
flicker her losing the two that you gained however you can now do that infinite times and win.
If your friends are running tokens you might want to consider running
Amulet of Safekeeping and you should definitely run
Cyclonic Rift.