Quick answer — Linked Horizon performed 2 anime themes, including "Guren no Yumiya" from Attack on Titan, "Shoukei to Shikabane no Michi" from Attack on Titan Season 3 Part 2.
Linked Horizon performed the anime theme songs "Guren no Yumiya" (Attack on Titan), "Shoukei to Shikabane no Michi" (Attack on Titan Season 3 Part 2).
Linked Horizon's first listed anime theme is "Guren no Yumiya", the opening of Attack on Titan.
