I voted for one attunement only. As long as you only have 3 casts, spam should not be too strong of an issue, since you would expend everything in one go, and if you miss even one you will likely have wasted said spam because your opponent will have time to dodge or start blocking the rest. It also promotes its use in a more defensive manner, forcing you to strategically decide on how you want to use it (either as a damage source or an interruption force) instead of as a main damage spell.
Last edited by Reaperfan on Mon Mar 19, 2012 12:26 am; edited 1 time in total