Vecna has a major fashion problem...
…and it's not the fact that he only has 1 cosmetic (but god I'd love to see him get more).
It's his addons, all of the addons that are either robes or cloaks are SUPER bad. They don't really do anything of use, and for some reason, the purple ones were NERFED from the PTB.
Anyway, here's how I'd improve them:
Cloak of Elvenkind
8m TR reduction only while flying… In what world will this do anything?
I'd update it to grant Undetectable while Flying. It won't give him complete stealth since he's SUPER loud while flying anyway, and there's a good handful of green addons that grant Undetectable anyway.
It'd also partially counter the associated magic item. You'd still get the notification when he starts flying, though.
Cloak of Invisibility
It's extremely rare that all 4 Spells will be on cooldown at once. This is due to the fact that Dispelling Sphere has little use in a chase, so there's not much point in using it.
I'd change it to only require 3 Spells to be on cooldown, and increase the duration to 15 seconds. This would be a nice reward for using your spells effectively.
Robe of Eyes
The detection radius is far too small to see anyone the majority of the time. I'd increase the radius to 12m, but maybe only extend it to unopened chests to compensate.
Ring of Telekinesis (Bonus Round)
(It's an accessory, it counts)
This reworked addon is very much not good at all. It's far too undertuned, but the concept might be useful. I'd increase the numbers to 20% and maybe 15-20 seconds.