English may not be your first language, but please make an effort to at least use proper capitalization and punctuation (ellipses are misused 99% of the time, simply avoid them).
it is better for ALL Single-Target Fights (like the Morchok/Ultraxion/Blackhorn) use (397)Crache + (390)EoU?
And leave the R-Skull for fights that need Burst dmg(including Warlord Black Phase).
Rotting Skull seems a nice trinket ... but in the long term it seems less than LFR EoU.
in this case ... Whereas the combination of Creche+EoU will always be better, even being LFR or not, spend 1650 Valor Point would be the last option?