Hi there
I was a bit surprised by this topic (now i don't consider myself a power gamer by any means)
but i made a multi class soulblade/bleakwalker bit of a one trick pony perhaps but i find
it very effective and fun to play.
And ok i ignore all spells except body attunement.
Well wat can is say i don't think this multiclass is weak in any way
(please note this is only my opnion)