I had an idea for a replacement to Sole Survivor, since it's pretty bad at the moment. I'll leave it to those better at theory and number crunching to see if this is OP or not, and it's just a suggestion, so try not to rip my guts out over it
Blood Feast:
Level 62
Cost - 30 Blood
Duration - 5 seconds
Recast - 40 seconds
No stance requirement
Self-only Heal - 20% HP (or an equivalent to a BiS geared HP, could even be a HoT)
Mana Instant - 10% Refresh
Mitigation - 10% Physical and Magic (5 seconds)
Animation could be something along the lines of a blood red aura, eyes turn red, etc - just not something that would require clipping to keep from being animation-locked is fine.
Anywho, probably a stupid idea, but I felt it would be something that would help alleviate a lot of issues for the Dark that have been spoken of here, and wouldn't require too much re-balancing of the other skills we currently have now. Tying it into blood usage would fit thematically, and would be something a dark knight should be able to do. As it stands, I have only used Sole Survivor like once in a dungeon while leveling, and pretty much forget about that skill being on my hot bar most times. replacing it with something like this would be a good way to help any post-60 darks leveling, while still keeping with the lore. I'd also like to see Shadow wall dropped to level 35, and have its recast timer dropped to 2 minutes, to be in line with the other major mitigating skills.