Spell hunter

Martial talent

You have developed a knack for disrupting even the most skilled spellcasters. You gain the following benefits:

• When a creature you can see within your reach casts a spell, you can use your reaction to make a single melee attack against them. On a hit, the attack deals additional damage equal to the number of mana points being spent on the spell being cast. On a critical hit, the spell is interrupted and isn’t cast, though the mana point is not consumed.
• While within 1 square (1.5m) of a creature, you have advantage on saving throws against their spells, and they have disadvantage on saves to maintain concentration.
• While grappling a creature, it cannot cast spells that require a somatic component.