When I go magblade, I have a decent time sustaining with funnel health. The cost isn't that huge of an issue tbh.
Okey first! @Mystrius_Archaion, lol at that signature.
Not everything in this world is meant as an attack, the lol could be for countless things. But you assumed it was an attack?
I just found it abit lol. Nothing more, nothing less. Ait?
Strife and its morph have a hard time to compete against other spammables for magicka nightblade since its significant cost increase. One reason the morph swallow soul doesn't make it into my build is that the unique minor vitality buff only applies to the bar the skill is slotted on.
A small and simple change to make the skill more attractive would be to grant the minor vitality buff while the heal over time is active, which allows access to more healing on both bars.