Battle cry (Whenever this creature attacks, each other attacking creature gets +1/+0 until end of turn.)
At the beginning of combat on your turn, the next time target creature would deal combat damage to one or more players this combat, prevent that damage. If damage is prevented this way, create that many 1/1 colorless Phyrexian Mite artifact creature tokens with toxic 1 and "This token can't block."
Ria Ivor turns one big attacker into an army of toxic Mites by converting that creature's combat damage into 1/1 toxic tokens each combat, then buffs the whole team with battle cry. You build a wide aggressive board, pump a single creature huge, prevent its damage on Ria's trigger to spawn a swarm of Mites, and swing for poison and damage. The deck snowballs through repeated combats, anthems, and token doublers to overwhelm tables fast.
Generates a wide toxic token army that wins through poison counters rather than life totals
Battle cry plus go-wide tokens makes alpha strikes lethal quickly
Damage-prevention trigger turns big trample/power creatures into more bodies instead of wasted damage
Black-white access to the best removal, anthems, and recursion in the format
Relies on Ria connecting in combat; she's a 4-mana commander vulnerable to removal and chump blocks
Board wipes are devastating to a token-centric strategy
Toxic clock can be slow without extra combats or doublers, giving control decks time
Limited card advantage engines compared to other BW strategies