Relic of Progenitus has been one of the premium answers to some strategies: Its cheap, and can play a grindy game removing one card per turn, or one-shot-exiling both graveyards at the right time
Talk with the judge staff and let them know your interest in case theyre given boxes for the event
The first triggered ability happens at the beginning of your upkeep and removes a time counter from the card
Given the number of ways to untap lands in green and how you can just as quickly pump out creatures and tokens, you can gain a ton of mana in no time
That means Yuriko, the Tiger's ShadowYuriko, the Tiger's Shadow and Ninjas, Reaper KingReaper King and Scarecrows, and even Voja, Jaws of the ConclaveVoja, Jaws of the Conclave and Elves and The Ur-Dragon, because getting to critical mass of your creature type is just that important
Atraxa, Grand Unifier made waves in most Constructed formats, why not this one too