Playable in Legacy and EDH alike, it costs only three mana and you can even decide to pay less mana and keep your bigger creatures alive
Secondly, I love seeing cards Im not familiar with on the opposite side of the table
As such, it has the most access to Fireballs, Lightning Bolts, and the best first strike and hasty creatures, like Fervent Champion
Seedborn Muse is a tough one to cut, but I figure the ability is just a little bit redundant with Bear Umbra, and I feel that the Aura works better with Gargos
While Warhammer is best used on the offense, it does have some applications for recovering from an aggressive foe
Emeria Shepherd works fantastically alongside other angels that can give it indestructible, like Avacyn, Angel of Hope