As it was the double daily for me yesterday, I figured I'd give heroic HoL a try on my 5 druid group (one resto, one bear, 3 moonkin). No issues anywhere up until Ionar (with the exception of the Slag guys which are immune to nature damage, forcing me to either swipe them to death or use starfire...ugh, waste of mana!).

Ionar - initial attempt:

I'd done him on Normal before, and I could heal through everything fine, I was treating it as if I was solo and doing the "run back down the stairs" thing, but would get hit by the ball lightning each time we came back up the choke point on the stairs. In Heroic, however, this caused a wipe almost immediately. Wasn't able to move the guys backwards fast enough, nor would I have been able to get them back into position fast enough had I lasted past the first disperse.

Ionar - second (and successful) attempt:

Now, I have my arrow keys set to control only my slave toons, where W,A,S,D,Q,E control only my tank (main). What I did, was kill the group of guys on the second balcony up, after the first little steps leading to Ionar. Then, arranged my team in a spread fashion, in a line, facing directly up the stairs. They were spread about 5 yards apart, directly in a line so they were all facing Ionar.

Pulled him, did the usual fighting and such, when he throws the balls out or does any aoe damage to a someone, it only affected them or maybe one other guy. When he dispersed, I immediately strafed left with my guys and manually moved with my main. I kept straffing left and moving with the group until the far left guy was almost touching the balcony. Wild Growth'ing as much as I could while moving just to ensure they're topped up. When the sparks came in, the right toon took a few hundred damage from a hit or two, nothing major. Strafe right with slaves, move right with main, get back into position, roughly.

Rinse and repeat!

After such a horrible death on the first attempt this was really nice to nail so easily on the 2nd.

Loken:

I use a very similar strategy for Loken, strafe out as a group the second I see his Nova, super easy. Bunch up on Loken, so no major aoe damage happens, and which means this works fine for melee as well (just don't bother getting behind him, that'd be too complicated for this strategy). Nova starts casting, strafe right with the group and your main, nova goes off, stay put. Loken will come to you, I just move over a bit closer to him when he's settled in for the next beating. Strafe the opposite direction on the next nova, rinse and repeat.

My healer doesn't have the power to heal through the nova otherwise, not boxed at least, so this was good stuff.

Maybe it's been said before but just incase, there ya go, maybe it'll help someone