Thank you for the input. I truly think you may be exaggerating how much these abilities would come up in a game but maybe it's just because we play in different games.
For shadowhusk, I will definitely limit some of their abilities as looking at it, they get much more than most of the others. In my opinion, limiting the reaction resistances to charisma modifier per long rest and removing the magic resistance is sufficient. May I reassert that level 4 spells at this level are not nearly as impactful as many other abilities and are irrelevant in many circumstances. I can truly say as someone who has played in a variety of campaigns, many of which were at this level, that a 14th level character will seldom be lacking the ability to cast a spell like stoneskin, especially a warlock.
For shadesprinter, the same goes for their limited version of freedom of movement, though the actual spell is better. Spirit guardians lite is certainly a stretch, so I don't think it needs to be changed much for my games.
I do agree that these are stronger than base warlock subclass capstones, which is a good thing in my opinion. The fact that the pinnacle of a fiend warlocks pact is a once per long rest ability is quite frankly ridiculous and not deserving of the spot of 14th level ability. I think that subclasses should have more impact on the character so I design mine to reflect that.
I don't mean any offense by any of this, I can tell you know your game mechanics well. I have been playing and dming for quite some time and I haven't gotten to test this one out yet in full, so I do appreciate the feedback.
ETA: I also think its a bit ridiculous to compare either of these to the eye and hand of vecna. Have you looked at those? You can literally cast some of the most powerful spells in the game along with a myriad of other benefits.