I recently promoted my Arvis to 5*, his valflame tome has atk/spd -4 debuff. I gave him atk ploy 2 seal hoping he will debuff the enemy by 8. However, during match up, enemy only get a atk -4 debuff. This happened with horse emblem as well, after receiving hone cavalry, unit is unable to receive other boost from hone atk or hone spd (basically with hone cavalry and hone atk, a unit atk is boosted only with +6). Is there are rule of how hone/fortify and ploy skill that I am unaware of?
Visible buffs/debuffs will not stack. If a higher buff or debuff is placed when one is already running, it overrides whatever buff/debuff a unit has running.
If you still want to give Arvis the Atk Ploy seal, it needs to be a level 3 if he's carrying Valflame; otherwise, the seal would be wasted space that would have been filled with something else. Fortunately you can take the seal off and give it to someone else painlessly.
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