it technically helps every class, just it helps strength the most by letting it go from near-useless to at least viable in pve
also most of the bosses are well designed around magic, sadly i dont think many of the testers ever thought to use berserker against bosses like allanon that have mile wide aoes that can kill you in seconds and fly to unreachable heights (especially without minmaxed builds or very little techniques outside of the base a couple rares since you realistically wouldnt have that much at that point in progression) or something like ormolu where if you arent distancing yourself then you’re also going to die in seconds.
I don’t think Lord Elius would need it but it feels weird to give the mechanic to the bosses that strength would struggle at rather than just applying it to everyone