Infinite card drawNear-infinite creature ETBInfinite draw triggersNear-infinite colored manaNear-infinite creature tokensNear-infinite untap of creatures you controlNear-infinite mana creatures you control can produce
How it works
Activate Karn twice by paying 2, causing Halo Fountain and Prismatic Geoscope to become a creature.
Activate Prismatic Geoscope by tapping it, adding at least .
Activate Halo Fountain's second ability by paying , tapping it, and then untapping it and Prismatic Geoscope, causing you to draw a card.