Quick answer — Takuma Terashima performed 1 anime theme, including "Reincarnate" from That Time I Got Reincarnated as a Slime Season 2 Part 2.
Takuma Terashima performed the anime theme songs "Reincarnate" (That Time I Got Reincarnated as a Slime Season 2 Part 2).
Takuma Terashima's first listed anime theme is "Reincarnate", the ending of That Time I Got Reincarnated as a Slime Season 2 Part 2.