Gray Merchant enters the battlefield, causing each opponent to lose life equal to your devotion to black, and causing you to gain life equal to the amount of life lost this way.
Cryptic Trilobite triggers, putting at least two +1/+1 counters on itself.
Activate Cryptic Trilobite's first ability twice by removing two +1/+1 counters from it, adding ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) ({C} magic symbol) that can only be spent to activate abilities.
Repeat.
Results
Infinite +1/+1 counters on Cryptic Trilobite.
Infinite blinking.
Infinite colorless mana that can only be spent to activate abilities.