If it isn't now it is going to be problem soon. Right now you have Flood/Edge taking 2 hot bar and produce no synergy. Same with Bloodspiller and Quietus. If you don't merge it now the next expansion you would have too anyway.


And for Abyssal Drain it doesn't give a blood gauge it only restore mp and give a stack of abyss which is a bullet for darkpassenger.
However if this version of Abyssal Drain does restore mp too fast then there is an alternate it could be like :
Upon landing Abyssal Drain restore 600 mp and grant a buff which make the next 4 gcd restore 600 mp upon landing but I prefer 1 hit and the job done if possible since I don't want to experience the nuisance when the target just decide to jump or teleport/became untargetable before I could land all the hit.


If you want to convince all the DRK main to not turn tbn to 25s and no mp cost then be my guest. I won't engage in that topic and I can't be convinced otherwise.