When fighting Gruul in BRF, we noticed increased incoming damage from Inferno Slice when some people launch damage reducing/avoiding abilities, such as Divine Shield. We are unsure which abilities are safe to use. My guess is, that damage immunities will make the damage be split among others instead, like mentioned DS or Ice Block from Mages. But what about Deterrence and others such as Evanesce?
Inferno Slice deals physical damage to the tank, and direct fire damage plus fire damage over time to players in front of Gruul. Here we're concerned with the fire damage to the raid.
Any ability which grants immunity to fire damage will exclude that player from the damage split. This is basically just Ice Block and Divine Shield, though there are obscure ones such as The Void, which you may randomly get from using a Last Deck of Nemelex Xobeh (which can be kind of risky in a raid environment).
Abilities which absorb damage or provide a damage reduction percentage (which is effectively the same thing) should be safe to use, as the damage is actually delivered, but consumed by the ability. These include:
- Death Knight: Anti-Magic Shell, Defile, Purgatory
- Mage: Flameglow, Ice Barrier
- Monk: Dampen Harm, Guard, Life Cocoon, Soul Dance, Touch of Karma
- Paladin: Ardent Defender, Hand of Purity, Holy Shield
- Priest: Clarity of Will, Guardian Spirit, Power Word: Shield
- Warrior: Shield Barrier
- Warlock: Dark Bargain, Sacrificial Pact
But I probably forgot a few. Obviously some of these aren't going to be very useful, and some are practically mandatory.
Whatever you do, the best strategy for dealing with Inferno Slice is still splitting the raid into two groups, one in front of Gruul and one behind, and alternating which group he hits.