Agatha's Soul Cauldron + Myojin of Towering Might + Tekuthal, Inquiry Dominus + 1 more
Infinite colored mana that can only be spent to activate abilities of creatures, Infinite colorless mana, Infinite +1/+1 counters on creatures you control
Activate Tekuthal using Myojin of Towering Might's ability by removing an indestructible counter from it, putting six +1/+1 counters on Workhorse, and two +1/+1 counters on any creature you control.
Activate Workhorse three times by removing three +1/+1 counters from it, adding .
Activate Tekuthal by paying and removing three +1/+1 counters from Workhorse, putting an indestructible counter on it.
Repeat.
Component Cards
How It Works
Activate Tekuthal using Myojin of Towering Might's ability by removing an indestructible counter from it, putting six +1/+1 counters on Workhorse, and two +1/+1 counters on any creature you control.
Activate Workhorse three times by removing three +1/+1 counters from it, adding .
Activate Tekuthal by paying and removing three +1/+1 counters from Workhorse, putting an indestructible counter on it.
Repeat.