Im thinking of taking arcane admixture,psychic for my icy skewer attack on my fey hexblade, then getting the psychic lock feat. He already gets 3 encounter attacks with the psychic keyword, all of wich grant invisibility to his target. so with psychic lock and icy skewers +2 to defences against targets attacks, he would be attacking at -4 to hit, add in the +2 from shadow blends partial concealment and i should be really hard to hit. Piercing shard and winters retribitive escape add invisibility to the +2 bonus from psychic so at least -7 to hit. my question is, are there any other feats or powers that could make me harder to hit, or otherwise cripple my target, and since ill be using frostcheese. will both lasting frost and psychic lock, work on the same attack work, thanks.