Orcish Bowmasters | Agatha's Soul Cauldron | Whirlpool Warrior

(and one other card)

Cast
Orcish Bowmasters by paying ({1} magic symbol) ({B} magic symbol) .
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.
Activate the Orc Army using
Whirlpool Warrior's ability by paying ({1} magic symbol) and sacrificing it, causing each player to shuffle their hand into their library, and causing each player to draw that many cards.
Orcish Bowmasters triggers for each card opponents draw this way.
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.
Activate
Phyrexian Altar by sacrificing the Orc Army, adding ({1} magic symbol) .
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.
Holding priority, repeat from step 3 an arbitrarily large number of times.
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.
Repeat from step 9 for each remaining trigger.