"Returns upon death, revives upon summon!"

What does that mean??

This meansit automatically de-summons when it dies. With the message "The cloud has seperated, it will be revived once you summon it again." And as that message states, it comes back to life when you summon it again.

What happens if it gets KOed while playing as the nimbus?

It just dies and gives you the standard revivial options (Town, Wait for Rescue, Revive on spot)

• There seems to be a slight glitch though, if it dies whle playing as it, then type "/logout", it will be revived, but only at half HP, the rest is wounds.

Sometimes mine does that too, but not when I'm playing it.