Conditions/requirements and Slayer (spoiler)

[teardropmina]

spoiler thread [img]smile.gif[/img]

I rarely turn my PC into Slayer. I recall, long time ago there were couple of times in the Illithid Lair, my PC turned into Slayer to open doors. now I would just charm a Mind Flayer in the Mind Flayer respwan room to do the job.
however, these couple of days I did the Imp. Irenicus battle; to fight Irenicus the Slayer, I tried to turn my PC into Slayer. The first time it worked, and there were times it didn't. Here is the situation: when I choose to turn into Slayer and I also lost two rep. points, yet, it failed! the feedback read: spell ineffective. It seems to me that it's because I have the Spell Trap form SoTM on and other spell protection/stoneskin on. When it succeed, all the magic protection on my PC was shattered/dispelled. I used a pre-fight save game to test, my PC can turn into Slayer with all kinds of protection on. Also, sometimes, in the process of turning, Irenicus the Slayer would hit my PC. Does his attack render the turning ineffective???
So, here is the question: does turning into Slayer count as Spell??? shouldn't the Slayer transformation count as the special innate ability of PC, and PC can choose to turn into Slayer at will?
or this is another bug of the Tactics?

[Lord]

Do you have the improved slayer stuff installed? That might be your problem. With that, you gain more control over the slayer when you hit something like 4 million xp, and you can turn into the ravager at 6 or 7 million xp.