Lissa

Lissa

Skill Set

	Dazzling Joyous Lantern+	A	Brazen Def/Res 3
	Rehabilitate+	B	Wrathful Staff 3
	Windfire Balm+	C	Spur Atk Spd 2

Hero Build Overview/Explanation

Unit: Default!Lissa
Nature: +Spd/-HP or +Atk/-HP
Weapon: Joyous Lantern+, Dazzling or Wrathful refine (dependent on Passive B)
Support: Rehabilitate+
Special: Windfire Balm+ or Miracle
Passive A: Brazen Def/Res 3
Passive B: Wrathful Staff 3 or Dazzling Staff 3 (dependent on weapon refine)
Passive C: Spur Atk/Spd 2
Seal: Spur Def/Res 2 (will be available during next Tempest Trial, will edit once that is up)

Joyous Lantern grants the ally with the highest Atk on your team Def/Res+5 at the start of the turn. When you heal that ally while your Special is up, you add Atk/Spd+6 to that. The two dual Spurs add up to an in-combat bonus of All+3, making for a total in-battle stat bonus of 9/8/9/8.
For herself, Brazen Def/Res adds to her already impressive balanced bulk. Giving her Wrazzle-Dazzle also puts her up to her best potential in battle, though you can replace her B with Live to Serve to take advantage of Rehabilitate+. If you already have an offensive stat buffing unit, or if you feel Lissa isn't safe enough, you can replace Windfire Balm+ with Miracle.
Lissa, having access to superboons in both of her offensive stats, can choose between Atk or Spd. Atk is better if you're looking for more damage with Wrathful damage, but Spd is better to prevent some enemies from doubling her during the Enemy Phase. Her best bane is HP, since you want to give her as much bulk as possible for Brazen Def/Res and you also don't want to sacrifice her (somewhat subpar) offensive stats; though she does have a superbane in HP, it's not going to destroy her potential as a tanky unit. Also, since she does have superbanes in both Def and Res, you're essentially cutting your losses with the HP bane.