Orcish Bowmasters + Agatha's Soul Cauldron + Whirlpool Warrior + Phyrexian Altar

Orcish Bowmasters

Agatha's Soul Cauldron

Whirlpool Warrior

Phyrexian Altar

How it works

1. Cast Orcish Bowmasters by paying 1.
2. When Orcish Bowmasters enters the battlefield, it triggers, creating a 0/0 Orc Army token if you do not control an Army, then putting a +1/+1 counter on an Army you control and dealing 1 damage to any target.
3. Activate the Orc Army using Whirlpool Warrior's ability by paying 1 and sacrificing it, causing each player to shuffle their hand into their library, and causing each player to draw that many cards.
4. Orcish Bowmasters triggers for each card opponents draw this way.
5. Resolve the first trigger, creating a 0/0 Orc Army token, then putting a +1/+1 counter on it and dealing 1 damage to any target.
6. Activate Phyrexian Altar by sacrificing the Orc Army, adding 1.
7. Resolve the second Orcish Bowmaster trigger, creating a 0/0 Orc Army token, then putting a +1/+1 counter on it and dealing 1 damage to any target.
8. Holding priority, repeat from step 3 an arbitrarily large number of times.
9. Resolve the first remaining Orcish Bowmasters trigger, if applicable, creating a 0/0 Orc Army token if you do not control one, then putting a +1/+1 counter on an Army you control and dealing 1 damage to any target.
10. Repeat from step 9 for each remaining trigger.

This ingenious loop turns a flurry of card draw into a self-sustaining engine of doom. By using Agatha's Soul Cauldron to grant your creatures the activated sacrifice ability of Whirlpool Warrior, you can force every player to constantly cycle their hands while repeatedly fueling Phyrexian Altar for mana. Every single time your opponents draw those new cards, Orcish Bowmasters triggers to rain down damage and grow your forces, which in turn provides the fresh sacrifices needed to keep the wheel spinning.