Prerequisite: Prana-Bindu 50
In flurry and katahzirui form you will sometimes gain a follow-on attack if one of your attacks is negated (through a defense skill, special ability, etc.). This follow-on attack will have a description like “you see through the defenses and attack”. Training the tenacity skill seems to improve the chances of gaining the follow-on attack and/or improves the damage of the attack. This skill is more effective for the katahzirui form, which has more of these follow-on attacks.