So you have to level up between castings, and you can only cast it five times in your lifetime? That's a pretty interesting way of limiting it.
It gets even more interesting: each time you cast it, it's more difficult and the side-effects are more severe.
It's a brilliant working of the spell.
Not really. There is this snippet at the end of the spell:If I understand the spell correctly, there is no upper limit on the number of times a particular character can be resurrected.
The bad news is that if the target of your resurrection spell has been resurrected more times than you have cast the spell, there is a nasty 50% chance that the experience will play out using their higher number of resurrections instead of the number of times you have cast the spell.