The ability to prevent life loss can also come in handy, although it wont save you from poison counters or commander damage
Or, just in the Aurora example, you can choose the warding princess as your target
But the real reason Bruvac is so powerful is that theres an entire class of card, all of the variants of Traumatize, that makes an entire player's deck go poof when resolved with Bruvac in play
If that sounds fake to you, show me another card that generates 10 power and toughness for six mana out of the can
Celestial Armor helps buff Cloud, Ex-Soldiers power, gives him evasion, and crucially acts as a protection spell, too
Being a dragon provides other synergies too for example using Crux of Fate for a one-sided board wipe