On my phone, so I'm basing this off of your screenshot.
The Panacea process is, on average, better than Miracle's unique, so slotting it instead of the Numina's unique will net you better endurance. Also, you could skip what I assume is the chance for heal proc in stamina and move that slot to health for all 3 uniques.
You don't need anywhere near that much defense on a /dark corr, between Darkest Night and Fearsome Stare, you need probably 30% defense at most to keep you effectively soft capped.
Oops, just noticed you have vengeance toggled on, so that's screwing with your defense numbers.
I'd probably try to get some resistance slotted into Shadowfall.