Battle Caster

The ability to cast a spell or cantrip

You have become an expert at casting spells in the midst of battles, learning advanced techniques:  

• You have an Advantage on Constitution-based concentration saving throws from sustaining damage.
• You can perform the somatic components of spells even when you have one or both hands occupied/in use/restrained.
• When a creature's movement provokes an opportunity attack from you, you can use your reaction to cast a spell at the creature, as an opportunity attack. The spell must have a casting time of 1 action or less and must target only that creature ONLY.