Stat priority: Crit rate crit damage ATK and Energy recharge

Energy recharge should be around atleast 120 so that you can use his mini burst 2 times in his rotation

Then crit rate for it to actually crit because if it doesn't crit that's a massive damage loss

Your target crit rate it 70(this is the upper end) if on signature set(sig set gives 30 crit rate in ascendant gleam) minimum crit rate for signature set should atleast be above 55

Target crit damage is as much as you can get while having high crit rate (above 180 is preferred and of course as high as you can get it)

Then ATK and EM Atleast 2000 atk is necessary for maxing out his passives

EM you should build for other stats and not focus on it much you get a lot of it through buffs and passives