Sakura is a strong Light element unit that brings 2 new jobs to the game: Sage of Mysidia and Kotodama Wielder. Her Sage of Mysidia main job gives her Light and Lightning elemental attacks, as well as being able to give a buff that resists Lightning, Light, and Dark in an area with just 1 skill. It doesn't provide much as a subjob, but the Kotodama Wielder does add to her strength since it gives her some mobility, damage increase buff, and a guaranteed hit ability. Her Master Ability is also a strong asset if you are planning on going for a mono Light team.
She's quite a strong unit to use in PvP due to her element and damage, but also because she counters a common unit often seen in the meta, which is Kain. Being a Light element means that she will do more damage against Dark units in general, but she also has innate 10% Pierce resist, and 50% to Slow and Confusion, 2 of the debuffs that Kain can use. On top of that, Sakura's strongest ability comes with an added bonus of ignoring skills that lets a unit survive fatal damage. Trousseau VC fits her quite well since it boosts Magic Attack and gives Dark Attack Res.
Deals 3-Hit Dmg (L) to targets within range based on caster's MAG stat & Dark Killer/