When it's on the battlefield, you get to attach any new equipment that enters the battlefield directly to a creature you control, eliminating the need to pay equip costs
Also, a shout out to another 2 mana tap for a big effect Gate, Basilisk Gate which can pump up a Commander by a bunch in a Gate brew, and win much more quickly with Commander Damage
They also benefit from synergies with spells and effects that manipulate the game's tempo, making it easier to trigger their transformations
The last perk this list has is the burst damage it can output
It might require a commander swap though, since Terra's just not maximized for the precon
Card Name Mana Cost Type Legendary Creature Elf Noble Rarity Rare rules Text Whenever Ayara or another black creature you control enters, each opponent loses 1 life and you gain 1 life., Sacrifice another black creature: Draw a card