Meeting of the Five

Exile the top ten cards of your library. You may cast spells with exactly three colors from among them this turn. Add {W}{W}{U}{U}{B}{B}{R}{R}{G}{G}. Spend this mana only to cast spells with exactly three colors.

Ramos, Dragon Engine

Flying
Whenever you cast a spell, put a +1/+1 counter on Ramos for each of that spell's colors.
Remove five +1/+1 counters from Ramos: Add {W}{W}{U}{U}{B}{B}{R}{R}{G}{G}. Activate only once each turn.

Threefold Signal

When Threefold Signal enters, scry 3.
Each spell you cast that's exactly three colors has replicate {3}. (When you cast it, copy it for each time you paid its replicate cost. You may choose new targets for the copies. A copy of a permanent spell becomes a token.)