Caster

About

Fate/Grand Order: Turas Réalta
He is the leader of the Resistance, which formed as a result of the atrocities committed by the Americans and the Celts.

Appears in chapter 38.

Fate/Grand Order: Epic of Remnant III - Shimousa
Appears in chapter 2.

Fate/Grand Order: Epic of Remnant IV - Salem
Leonardo da Vinci asks Geronimo to advise Chaldea about the Salem Singularity.

Appears in chapter 1.

(Source: TYPE-MOON Wiki)

Anime

Supporting Fate/Grand Order: Final Singularity - Grand Temple of Time: Solomon

Supporting Fate/Grand Carnival

Manga

Supporting Fate/Grand Order: Turas Réalta

Supporting Fate/Grand Order -Epic of Remnant- Pseudo-Singularity III: The Stage of Carnage, Shimousa - Seven Duels of Swordmasters

Supporting Fate/Grand Order: Epic of Remnant - Pseudo-Singularity IV: The Forbidden Advent Garden, Salem - Heretical Salem