A few small things:
- Abyssal Drain did not, itself, heal. If you want an Abyssal Drain that heals as it did before, it'd also cost you a third of your MP per use (combined costs of DA+AD). It also hit for barely more than Unleash, meaning it'd incur further opportunity cost relative to the Unleash-Stalwart combo.
- Abyssal Drain healed for little per target hit, and no serious content contains mobs enough to make it a noticeable source of healing per execute. If the sustain issue would extend beyond dungeoning alone, that probably isn't the right shape of a "solution" for the issue at hand.
- Returning Abyssal Drain to the GCD will cost you its present free 240n potency and 200n cure potency per minute (or, at opportunity cost of just a flat 510 potency -- a bonus of at least 210p and 600cp by 3 targets).
Now, you could craft an improved/revised spammable-GCD Abyssal Drain, but still... why necessarily have it on the GCD at all, instead of just having it, say, replace Flood as a spammable oGCD?
It also removed an entire combo (Shadowfang as a two-step DoT combo), replacing it with a Sonic Thrust knock-off.
Sadly, it necessarily would. If the activator is to be used within the two-minute burst cycle, the only way for its second-stage oGCD (a la Salt and Darkness) not to also be used within that period is to literally run out of weave-space, which would mean the problem is already as bad as it can get and DRK would have no room for defensives over its two minute bursts.As long as they make the combo OGCD's work in a way that doesn't make the already bloated opener/2m worse, I'm for it.
Granted, if you wanted to rein back the burst APM and spread it over the lulls instead, the solution is pretty simple: Slap a mana cost onto Shadowbringer and Carve and Spit, increase their potency accordingly, and then increase MP generation to compensate for the extra 6k MP consumed per average minute while toning oGCD damage down also in due compensation (i.e., for the same total DPS under a meta comp). Total APM and DPS stays the same, but there are now fewer Edges bloating ones burst casts (despite keeping almost exactly the same burstiness), and more to do between burst cycles.