Sephara, Sky's Blade

The alternative cost is where this Angel earns her place in the cheat-a-fatty tradition: instead of seven mana, she asks for a single white plus tapping four untapped fliers, which means a wide Angel or Bird board can drop her the turn it stops needing every attacker on offense. That payment structure carries the entire design. She rewards you for already fielding a flying army, then turns around and makes that army functionally unkillable, granting indestructible to every other flier you control the instant she resolves. The self-exclusion is the balancing wrinkle: her own 7/7 does not get the indestructible she hands out, so board wipes and single-target removal can still hit her, which keeps the umbrella from covering the piece that anchors it. The alternative cost is not Convoke, either; it is a bespoke reduction demanding exactly one white and four flying creatures tapped, so the pilot chooses between hard-casting her while the swarm keeps swinging or tapping the swarm down to land her cheaply and anchoring the board she just protected. Lifelink on an evasive 7/7 tilts damage races by itself, but the reason she matters is the sequencing question she forces on a go-wide flying deck: hold the fliers to hard-cast, or spend them to summon the very card that shields them the moment she hits. She is the payoff a tribal flying strategy builds toward, not the card that starts one.