Whenever a player attacks with three or more creatures, you draw a card.
Whenever a player attacks with five or more creatures, Aurelia deals 3 damage to each of your opponents and you gain 3 life.
Deploy a wide, fast board of creatures and attack every turn to trigger Aurelia's card draw and Pinger ability. You snowball card advantage off go-wide aggression while the 5-attacker trigger pings opponents for life-drain damage that closes games. Aurelia herself is an evasive haste beater that also rewards your opponents' attacks since the triggers say 'a player.'
Refills your hand every combat once you have three attackers, beating the go-wide deck's classic card-starvation problem
Aurelia comes down with haste and immediately pressures, with flying/vigilance keeping her relevant on both ends
The 5-attacker trigger is a repeatable group-drain that punishes the whole table and stabilizes your life total
Triggers off any player attacking, so politically you can benefit from others' aggression too
Heavily reliant on a developed board, so board wipes set you back hard
Vulnerable to fogs, ground-stalling, and Propaganda/Ghostly Prison effects that tax attacks
Boros lacks ramp and card draw outside the combat triggers, so a slow start hurts
If Aurelia is removed repeatedly, the deck loses its engine and grindy reach