wait, isn't hold skill for shenhe are for charged/normal attack? or it could be also used for burst as well? cause as far as i know if you want to buff burst damage you have to just tap shenhe's skill, and vice versa if you want to buff normal/charged atk you have to hold it.
She buffs all Cryo damage with her tap skill and with the hold skill buffs that plus a little more normal, hold and plunge. You usually just tap the skill if the rotation is going to be short (skill cooldown is longer if you hold)
