Guild Feat - Riot (Gruul Clans)

Imbue a creature with a fleeting burst of strength as they strike. When a beast, giant, or humanoid you can see within 60 feet hits a single target with a melee attack, it becomes an autocrit and does 1d12 more damage of the type dealt by the attack to that target. This attack deals double damage to a structure. You can use this ability once per rest.