Saruman triggers. Holding priority, if you control an Army, activate
Phyrexian Altar by sacrificing the Army, adding ({B} magic symbol) .
If needed, repeat step 2 until you do not control an Army.
Resolve the
Saruman trigger, creating a 0/0 Orc Army creature token and putting two +1/+1 counters on it.
Activate
Chthonian Nightmare by paying ({E} magic symbol) ({E} magic symbol) , sacrificing the Orc Army and returning
Chthonian Nightmare from the battlefield to your hand, returning
Orcish Bowmasters from your graveyard to the battlefield.
When
Orcish Bowmasters enters the battlefield, it triggers, dealing 1 damage to any target and creating a 0/0 Orc Army creature token and putting a +1/+1 counter on it.
Activate
Phyrexian Altar twice by sacrificing
Orcish Bowmasters and the Orc Army, adding ({1} magic symbol) ({B} magic symbol) .