Hey, I wonder if a servant has burn, poison, currse effect on normal attack like Jeanne Alter berserker use her skill then I put a Burn command code on that attack, so do it iflict 2 burn status on enemy ?
Yes the effects stack. Damage over time teams make use of this mostly to meme since the damage is pretty negligible otherwise.
Though varying Servants can make those stacks of burn/curse/poison do more damage with another debuff that does what i just said.
One thing to note though if you are collecting burns for use with honey lake, CCs apply burn before hit, and things like jaltzerker’s burn on hit apply burn after hit. So CCs get trait damage with goney lake immediately but the other won’t get bonus damage until the second hit. If face carding vs lots of mobs, the difference is significant as the latter often wastes the bonus of honey lake in bad rng, or not enough hp remaining by hit two to not matter