Another exploit for creature tutors are combos
Armix gets to control the board, which also helps it keep attacking to discard more cards on future turns
This card might take the prize for having the most on-the-nose name, but its a very powerful effect and one that only gets better as more artifacts get released
That said, if your deck does run Equipment, +1/+1 counter effects, or anthems, Esper Sentinels tax can get truly untenable, virtually guaranteeing you three or more cards per turn cycle
All that combined makes it a very fun card to play
By locking down colorless mana and colored mana sources alike, it can stop your opponents from activating their lands for mana entirely, which practically warps the rules of the game in your favor