I'm not sure it has been said already but on Valiona & Theralion encounter (Heroic Mode), Smoke Bomb doesn't work on Twilight Blast both in and out of the Twilight Realm. What a shame...

Chimaeron HC:

If you use cloak exactly 14 seconds after the feud starts (start a stop watch timer or count to 14 after the massacre), you will immune the first slime. If executed correctly, use cloak instantly when it comes off CD and you will immune the first slime in the next feud. You can do this for the first three feuds. I recommend using the fourth cloak to remove Mocking Shadows in phase 3.

Additionally for Chimaeron heroic:

If you find timers unnecessary or clumsy, you can use the Double Attack buff during Feud as a 5-second warning for the first Slime, i.e. a handy occasion to use Feint.

I'd also argue that cloak is better saved to get rid of the debuff from the last Slime to increase your damage output rather than mitigate Feud damage, since you are already taking far less damage than non-rogues, and a Massacre is imminent anyway so walking out of the Slime casts with extra hp is redundant. This is from a 25m perspective where you're bound to get sufficient healing from AoE heals that will be cast on the group-up spot regardless of your own health level (YMMV of course).

Feud is random, so this won't work by using it on CD.

As has been stated elsewhere (unless hotfixed in the last week, I can confirm from personal experience) feud is every 2-3 massacres, so you are not guaranteed to have cloak up for every feud.

Feud comes in beginning after 2 or 3 Massacres and after that it comes after 1 or 2 Massacres (heroic mode). Good way to time Feint and CloS with Feud Volleys is to Feint immediately after Massacre when Feud starts channeling. This way Feint comes off cooldown just before first volley lands and you can use Feint cooldown as timer when to Feint.

You can time CloS for second volley by activating it second or two after first volley or by watching Chimaerons animation (pretty easy to do) and then again Feint for third one. Or you can try to delay first Feint as much as possible and still have some of it's mitigation for second volley while saving CloS for third volley so you get rid of -hit debuff. Clearly if Feud happens back to back you won't have CloS cooldown for every Feud.

Does the Cloak glyph reduce Quake damage in the Twilight Ascendant fight?

Could you clarify this point a bit more.

Are you saying that the melee *did* get mindcontrolled...but did not channel the spell? Or that none of the melee got targetted during smoke bomb.

The former sounds more like a bug then the proper interaction of the spell given that Cho'gal should be able to target people he's in melee range of, but we killed him last night, so I can't test this until next weeks reset.

Magmaw Heroic:

• Lava Spew can be immuned by using cloak*.
• Lava Spew's damage can be reduced by feint.
• You can also cloak and feint the shadow bolt volley(aka Shadow Breath) that Nefarian does at <30%.
• You can cloak Blazing Inferno (which is the meteor that spawns the add), but it's pretty useless since you're still going to take damage from the Ignition afterwards.
• You cannot cloak-immune Ignition (fire on the ground that the adds leave).

Edit: *For some reason you can only immune 1 tick of Lava Spew when using cloak. I've tested in numerous times it would only allow me to immune one.
Edit2: Oh, and I don't think Smoke Bomb prevents you from being hit by the shadow bolt volley.

You can only ever immune 1 of anything each time you cast cloak. That's because you're immune to everything the instant you cast cloak. For the rest of the duration, you have a 200% chance to resist spells.

I've tried cloaking and running through it two or three times and it didn't work.