Lyra Dawnbringer gives an Angel deck both a formidable individual creature and a useful team bonus. Flying, first strike, and lifelink make her effective in combat, while your other Angels receive +1/+1 and lifelink.
Resplendent Angel is a particularly direct partner. Five damage from Lyra gains five life, meeting Resplendent Angel's threshold for an Angel token at the end step. Other Angels with enough combined damage can achieve the same result once Lyra grants them lifelink. Archangel of Thune adds another payoff by converting life-gain events into counters across your creatures.
First strike often lets Lyra gain life before regular combat damage happens. That can improve a race or let her defeat a blocker before it deals damage back. She still needs to deal damage to gain life, so damage prevention and removal before combat damage can interrupt that plan. Five mana fits well as a substantial midgame play in Angel and life-gain decks. You do not need a complicated combo for her to contribute: an evasive lifelink attacker can stabilize a board on its own. In a dedicated Angel list, however, her biggest impact often comes from making several existing creatures hit harder and gain life together, turning a favorable attack into a much safer position afterward.
