Focus on "Mana Vein Grafting." This increases your total MP pool, allowing you to spam Lune's "Lunar Flare" ability without running out of steam in longer dungeons.
Heart of the Void, Ocular Overload, and Eldritch Limbs. extreme modification magical girl mystic lune guide
Use Starlight Shackles to root enemies in place, followed by Void Collapse for a 300% damage multiplier. Focus on "Mana Vein Grafting