Board Thread:Questions and Answers/@comment-3250527-20140627033401/@comment-3030535-20170726100852

Chronoforge wrote: Thinking about it Klein still had it and there was no mention of him ever using it...

If a manga I saw once (It might be an unofficial one) is to be believed, Kirito, who was very low on HP after fighting the boss, fell down right after he gave the item to Klein, and died, Klein used it then and there.

Either way even if Klein still had it, he can't exactly move to use, and if Kirito still had it, it's going to be hard to use an item that fast while a paladin is swinging his sword at you, and it's improbable that either one still have that item anyway, as they would've most likely used it on the next dying person they can save