sideDamage

protected static void sideDamage(Player player, LivingEntity target, double damage)

Skill damage on top of the weapon's hit. It cannot trigger weapon skills again.

It lands outside the vanilla hurt cooldown and puts the target's cooldown back afterwards. Otherwise a follow-up within 10 ticks of any hit at least as strong (an Echo Bolt at the edge of its window, the next Starfall bolt, a party member's sword) was silently swallowed.