Q about the Abbot and concentration checks

[sirgog]

You have a 33% chance of that happening after every inferno, which means you very have chain infernos become uncommon (eg there's only around an 11% chance of inferno x inferno x inferno, so you'll only see it once or twice on average every 20 completions). Mord's dj has actually made the raid -drastically- easier, moreso than anything else that was changed about it. The odds in the prior attack chcain were 25% to see inferno x inferno x inferno, and still higher to get 4 in a row (12.5%) than the present chance of 3 in a row.

Isn't summoning two Phase Wraiths another thing he can do every 15 seconds?