Tested this pretty thoroughly today vs a willing enemy sorcerer. When the sorcerer had harness magicka or hardened ward up, the only effect the destructive touch skill (first one in destruction staff line) had was its initial damage; the CC effect of the knockback/stun was negated as was the damage over time effect.

I believe this bug is specific to the destructive touch skill as other form of magicka CC attacks, such as stonefirst and fossilized, worked against a shield using sorcerer. Also, the unstable flame and fire breathe dots also worked normally.

During these tests I noticed that the Valkyn skoria set never procced against damage shields. From what I remember, the issue of "hits" registering against damage shields that triggered ultimate game was resolved. I am wondering why there is an inconsistency in mechanics here. If attacks against damage shields are to be considered hits, then they should proc anything dependent on a hit (for ex., the siphon spirit skill). I say this as an unabashed shield stacker. These defenses are quite good as it is, they should not be providing free CC immunity vs destruction staves nor prevent opposing players from generating the procs they need and count on to make their builds effective.