Perseverant

You are determined to do anything that you have to do and can turn your intent into power:

• Increase your Strength, Dexterity, Intelligence, Wisdom or Charisma by 1, to a maximum of 20.
• Once per long rest, before you make an attack roll or cast a spell you can channel Perseverant and double the damage of that attack or spell.

The player has to call out that they are using Perseverant before they roll for the attack or the enemy rolls for the saving throw.