His brute strength is tempered by a strict code of honor passed down from his ancestors
Deck Contents Dropping +1/+1s [13 + 2 Lands + 1 Draw/Removal + 1 Wincon] We want to drop lots of +1/+1 counters, and there are quite a few humans who help with this agenda: [Card]Juniper Order Ranger[/Card], [Card]Metallic Mimic[/Card], [Card]Anafenza, the Foremost[/Card], [Card]Thalias Lieutenant[/Card], [Card]Mikaeus, the Lunarch[/Card], [Card]Deranged Outcast[/Card], [Card]Obsessive Skinner[/Card] and another incarnation of Reyhan in [Card]Dragonscale General[/Card] (the Game Day promo has a striking similarity)
While its on the battlefield, your opponents artifacts and enchantments cost two more mana to cast
Waiting to gain life from Wall of Reverence, another end of turn trigger, wont work because we have to choose the target when we put Celestines ability on the stack
Of course, the older legend cards were created before the Commander format was even invented