I don't know if this has happened to anyone else, so I thought I'd just put it out there. I am a level 48 Myth. I have used my myth prisms a lot when soloing in DS and Ravenscar. And lately they don't always work. And no, there are no storm shields involved--I'm always careful to take those off first. It will say "convert myth to storm," but then the damage is what it would be if I only got 20% of my hit--i.e., if I hadn't used the prism at all. This doesn't happen every time, but it's happened at least three times in the last two weeks, if memory serves. Anyone else have prism problems? Is this a glitch, or am missing something?
For Minotaur and Orthrus, you need TWO Prisms- one for each attack- otherwise you will not get the full convert, only the first, weak attack will get converted.
It would help if you could remember the boss or creatures you were fighting. For instance in The Grotto there is a Storm boss called Cuthula who curiously enough does not appear to have any storm spell resistance.
Myth shields cast AFTER your convert will also block your spell damage.
For storm shields you only have to worry about them if the opponent puts up a storm shield prior to your convert. However, if someone other than the targeted opponent with the convert on them casts a storm shield also on the targeted opponent then it will block the damage even if the convert was placed first. (That is, if a minion casts a shield onto the boss who already has a convert on him.) Confused yet? :?
Aside from that I haven't noticed any converts not working. Well at least for Fire and Life. It has been too long since I used Myth but I don't remember having that problem.
Thanks for those helpful replies. It didn't occur to me that there are two attacks-two prisms are hard to come by, but I'll remember that for the future. I guess the upshot is that it gets exponentially harder to fight guys in your own school, the more you advance. :(