Smells like old Defiance.
It surely does, but the main difference is that the damage buff is constant
I'd like to think it as a superior version of Absorb Pain. Share Pain's heal is about 80% of Absorb Pain's heal, but the -regen and 100% heal resist only last 15 seconds instead of 20.
Damage buff is just gravy!
It's not quite superior. Pain Domination, even if it were available as a primary, would never surpress Empathy in healing. But on the other hand, we can buff damage way better and grant resistance to all.
While fighting, I start with Share Pain on the Brute or whoever takes the Alpha and then attack for 15s before I use Share Pain again on someone badly injured that I didn't heal on purpose.
Of course, at distance.
I was talking specificly about Share Pain, not Pain Domination set as a whole.
I think Share Pain is superior to Absorb Pain because
<ul type="square">[*]Share Pain still heals very much, even at around 80% of it, enough to bring almost anyone from the brink of death.[*]Heal/Regen debuff lasts only 15 secs instead of 20. [*]It has a damage buff for you (yay!)[*]It's frikken red.[*] Edit: it also damages you less than Absorb Pain![/list]
It might heal worse, but other aspects make it clearly the superior version, and way more friendly to a Corruptor playstyle.
Ah yes, you're right. My whole playstyle is defined by this power. And it's frikken red!
And Slot-friendly. 3 Heals is enough IMO.
I can hardly believe that only two people mentioned the most important point so far, so let me repeat it for emphasis: It's frikken red!
Damn, now I am so hyped up about Pain Domination that I can hardly wait until my pc is up and running again. I am so going to have a new corruptor... or a MM... or both.
If it has eyes, you can blind it, if it has blood, you can make it bleed, if it has a mouth, you can make it scream.
Tried both, Corruptor wins 
Let's see if I got this straight:
Share Pain gives me a 25% Dam Buff after a massive ST heal, but leaves me unable to recieve any heals (including mine) and also damages me. Soothing Aura won't help me.
There's also a regeneration debuff, I'll be able to count only on Health for example.
My point: running Share Pain 100% of the time will add a nice damage boost but will eventually kill me. It's possible to stack it 2 times, which would grant a 50% damage bonus but halt any healing or regeneration.
In other words: a power that will let me die slowly while killing everything around me. Very poetic. I can already imagine /Pain Corruptors using this strategy and stop right before health is critical only to heal themselves.
Or I might be totally wrong;