changeling cards mtg Hero [Lorwyn] Until the end of your next turn Omni-Changeling

It also adds green regardless of what your creature taps for, so you can tap for green and another color if you have a Birds of Paradise

This can +2 to draw a card and scry two which is nice card flow, and then -3 to exile the top card of your library and then make a number of 1/1 flyers equal to the mana value, which is also very strong in Type Four with its elevated casting costs and low land count

60 Cards per Monocolored Section (300) 6 Cards per Dual Color (60) 3 Cards per Tri color (30) 3 5 Color Cards 57-60 Artifacts/Colorless 27-30 Lands Before deciding on what cards to go in, decide how players are drafting and constructing their decks

Needing to play a bunch of creatures, needing to wait until your upkeep, and needing to pay two life to draw the card all constrict the power of Call of the Ring just a bit, but for two mana, this can easily fit into all sorts of decks