My defense is at 30%, which is the only thing that will prevent you from losing a charge of Kinetic/Dark Ward. Since you only get 8 charges, at 1 slap every 1.5 seconds, statistically you would lose all 8 charges on the third attack at 4.5 seconds, not counting the additional attacks you receive, like slams from the other tentacles, etc.
Kinetic Ward has a 12 second cooldown, I think?... so you'll only have it up around half the time.