Life Drain, Twlight Grasp & Black Hole

I thought I hit these three all at once here with my Corruptor. I currently have Twlight Grasp and love what it does in solo and especially in team play with the nice healing buffs it gives. I was thinking about also getting Life drain but, it seems it does the same thing but also says that some of the stolen life is transferred to you in the form of hit points.

First, would it be beneficial to me to get Life Drain as another healing buff or would it be a waste of power being that I have Twlight Grasp?

Second, on what I read on Black Hole, it will Phase Shift your foes to make them completely intangible. They cannot be affected or affect those in normal space. So, with that being said, when and where would this power be practical? I was trying to place myself either in group play or solo and was wondering when this power would be beneficial? My thinking is this: in solo play, if you are going against an EB or AV and you are about to run out of end, Black Hole them and wait for your end to come back up. In group play, when your teammates are about to get slaughtered, Black Hole the foes before there is an all out slaughter. Then, regroup and begin again. Would this be the best way to use this power and/or is there any other good suggestions on the best use of this power? Thanks in advance to those who reply.

Twilight Grasp is an awesome heal as it debuffs their tohit as well, decreasing your need to use it a bit, so life drain might be a bit much. But the key to survivability with Dark is killing their tohit and have then swinging at shadows.

Black hole is your Holy **** button when you get in a jam. you can't touch your foes but they can't touch you. I forget how long it's for exactly but it givs you enough time to bail and rest if you pull it off. Never use it in teams though, Tanks hate that stuff lol.

Hope it helps =D

BH is a good power for an emergency, like an ambush that you're not prepared for. It's also good to separate a boss from his spawn, as unslotted for Intang, BH won't grab a boss mob or higher.

I use BH every once in a while on my teams during LRSFs and other high level TFs to counter nasty ambushes while I wait for DN, FS and Tar to come back. You can still apply DN to things that are phased, so when they come back, they're well screwed.

Life Drain is a weak heal; useful for sets that don't have a better heal in their secondary but best skipped with a /Dark Miasma. Black Hole is generally considered the most skippable power in /Dark, and widely hated by teams but as seen above some like it.