With all cards in play, equip Willowdusk with Umbral Mantle and cast Weather the Storm to gain 3 life.
Activate Willowdusk's ability by putting 3 +1/+1 counters on Cryptic Trilobite
Remove 2 counters from Cryptic Trilobite to add 4 mana.
Pay 3 mana to untap Willowdusk with Umbral Mantle
Repeat the process for infinite power and infinite mana.