Cossacki's Venom

You have achieved a penetrating precision in unarmed combat, as you fingernails become can venomous talons. 

• Once per turn, when you hit a creature with an unarmed strike attack that deals slashing damage, you can reroll one of the attack’s damage dice, and you must use the new roll.
• When you score a critical hit that deals slashing damage to a creature, you can roll one additional damage die when determining the extra slashing damage the target takes.
• when you successfully attack a creature with an unarmed strike, you may use 1 ki point to add 2d8 Poison damage using Cossacki's venom.