I'm having trouble finding what craft essence that's optimal for boss battles and general use to be put on Prototype Cu. I was thinking something on the line of Holy Night Sign or Seal Designation Enforcer to boost his critical damage and to give him stars. I have Volumen too, but I'm not sure if it would be as beneficial on him than FSN Cu
It will really depends on your team composition. If you have a critical star generator (ex: jack,curse harm hassan,fuuma,...), go with holy night sign that boost both the quick and critical damage. If you don't have a critical generator, put a CE with quick enhancement (imaginary around or any equivalent)
If you plan for a quick battle by firing the np as fast as possible, equip him with a CE with np charge (kaleidoscope or imaginary element).
Anything crit up/quick up. Holy Night Sign is about very fine.
If you max leveled his first skil, maybe go full quick with Immaginary around/MLB Gandr.
Beast Slayer gives decent star gathering up for 3 turns if you do his strengething quest...unless you wanna crit every time possible, dont do seal CE.
For fast fights, that Heavens Feel (not the Justicae one, the Sakura one), from HF campaign, with 40% starting bar and 10% quick up is a fine deal as well. Pretty much a lowkey Knights of Marines, for free.
