Shell Reflex

Your time in battle has heightened your senses and leaves you on guard when in a fight. You gain the following benefits:

• Your shell hardens. Your natural armor increases to 18.
• You learn to reflexively enter your shell as a form of defense. When another creature you can see hits you with an attack, you can use your reaction to activate your shell defense trait (you do not fall prone until after the attack hits or misses). You can do this a number of times equal to your Constitution modifier between short rests.