Conditioned Defense

Hardy and resilient from combat, you gain the following benefits:

• +1 AC
• +1 to Constitution saving throws
• Your hit point maximum increases by an amount equal to your level when you gain this feat. Whenever you gain a level thereafter, your hit point maximum increases by an additional 1 hit point. 
• Your body has grown to feel the magic energies at the moment they are cast and automatically respond; your skin becomes hardened to damaging spells. As a reaction roll a Constitution DC 10+spell level; on a success take no damage and on a failure take half damage. You may use this action a number of times equal to your Constitution modifier (minimum 1). You regain all expended uses when you finish a long rest.
• Your skin has grown so tough that even non-damaging spells can be resisted. As a reaction roll a Constitution DC 10+ twice the spell level. You may use this action a number of times equal to your Constitution modifier (minimum 1). You regain all expended uses when you finish a long rest.