Sacrifice it at the beginning of the next end step
I think early pack two is a good point to decide what to commit to, but again, it's way too early to delineate a successful strategy, so take this with a pinch of salt
Having enough cards that can get the proliferate train rolling is important and Teyos Lightshield is one you should keep your eye on
Keeps hyper-aggro honest while fueling Singer shells
At just 1 mana, it gives you , which can jump you into plays that normally shouldnt happen that soon
It reads, At the beginning of each end step, enchanted player mills X cards, where X is the number of cards put into their graveyard from anywhere this turn. It basically also doubles your mill, and while it only targets one player, its great if youre trying to prove youre not a threat