「たっぷりと、ご官能くださいませ」

EXTRAシリーズ好きを激震させたラスボスがまさか鯖化するとは思いませんでした…お出迎え出来て嬉しいです…

「Please enjoy all the pleasures it offers」

I never thought that the final boss that shocked the EXTRA series fans would turn into a servant... I'm so happy to welcome you...

<Tn>The words for servant (サーバント, "saabanto") and mackerel (鯖, "saba") have a similar sound in Japanese and are often used interchangeably. In this post it's literally written "would turn into a mackerel".
Though it wasn't an intended pun, Kiara got a summer version with fish traits in FGO years after this illustration was made.