Sniper Shot(d'artagnan) is -20% to attack and defense
Sneak Attack (granuaile) is -15% to attack and defense
JP Wiki has all values for buffs/debuffs - just use google translate
Thanks
You have a guide to use the wiki and link for the wiki if you don't mind. well it is not about using google translate it is about they're not using alphabet thus it is harder to navigate or search.