Mature gentleman is a limited CE only available in Kara no Kyoukai (The Garden of Sinners) event pickup summons.
For the duration of "Kara no Kyoukai (The Garden of Sinners) event", this craft essence gains additional effects.
Work in progress...
Rashoumon event (Ibaraki Douji event)
Murder at the Kogetsukan
Inheritance of Glory
Best Craft Essence: Craft Essence Tier List
4th Singularity: London
Device Transfer Guide
Best Servants [★4]: 4 Star Tier List
Fondant au Chocolat
Black Holy Grail (The Black Grail)