Whenever your Etheral goes down, he dies, and one of the markings from his hand will be peeled off, Much like a scab. Once an Etheral has no more markings left, then dies again, he will not come back. The only way for an Etheral to get a marking back, is to level up, but they only get one back. If the Eatheral already has no deaths, then he/she just stays at 7 markings.

Etheral get a +2 to str throws, and a +1 to con throws. At level 5, 10, 15, its increased by 1 for each.

Utilizing the runes left in your hand, you can help heal yourself, depending on the ammount of runes you have left, you could heal yourself. e.g. if you have not died at all, you get a +7 to medical rolls, if you only had one stone left, you would only have a +1. If you had no runes left, you don't get a bonus.