Titan strike

User bites down on their blade which causes the outer layer of metal to float a bit off the blade. Activating titan strike inflicts 3 damage to the user but empowers the next attack to deal an additional 2 damage per challenge rating (min. is chal lvl 1 for 2 additional damage and max is chal lvl 30 for 60 additional damage) enemies must roll constitution saving throw and if succeeded additional damage is halved.