What happened to Kirito's healing every 10 sec when he battled Heathcliff? In Sword Art Online after the episode &quot;The Black Swordsman&quot;, Kirito does not get any HP back during his fights with Heathcliff.
What happened to Kirito's healing?
Two possible reasons:

It was simply overlooked.  The fact that the battle was happening at all was probably more germane to the immediate circumstances than whatever abilities either player had.

It was probably underpowered compared to the DPS that Heathcliff could dish out, which is fairly common for MMOs to have an ability either become eclipsed by another one or made obsolete due to the people/NPCs being fought.  If it healed something like a value equal to the skill's level every 10 seconds, and Heathcliff exceeded that damage ratio, then suffice to say it wouldn't factor into the fight.