Both are great, but the Japanese voice actor (Seiichiro Yamashita) captures the "trying-too-hard" energy of Cid perfectly.
He is a chuunibyou (a person with "eighth-grader syndrome") who accidentally stumbled into being a god-tier warrior. The humor comes from the gap between his roleplay and the high-stakes reality of the world. Watch Kage no Jitsuryokusha ni Naritakute! Epis...
The "helpful" twist? Why this Perspective Helps Both are great, but the Japanese voice actor