Tromell, Seymour's Butler + Workhorse + Staff of Domination
Tromell, Seymour's Butler
Workhorse
Staff of Domination
Infinite colorless manaInfinite lifegain triggersInfinite lifegainInfinite card drawInfinite untap of creatures you controlInfinite draw triggersInfinite mana creatures you control can produceInfinite proliferateInfinite +1/+1 counters on a creature
How it works
Activate Tromell by paying 1 and tapping it, causing you to put at least six +1/+1 counters on Workhorse
Activate Workhorse six times by removing six +1/+1 counters from it, adding six C.
Activate Staff of Domination's third ability by paying 3, untapping Tromell.
Activate Staff of Domination's first ability by paying 1, untapping it.