Celestias get a blue slot if you upgrade them with the PDK favor into a Planar Conflux set.
I've been told this is because any sort of DR breaking effects (or augments) mess up their (Celestias) DR breaking. This includes effects like the Paladin's Weapons of Good, the weapon effects you get from certain destinies, and even Enchant Weapons (the only relevant effect I can see is that it gives an implement bonus). I think Deadly Weapons may be okay, but the other arti weapon buffs do break it.
Does anyone know WHY this happens (ie: have the devs told us?). Is this a coding issue or was this always the way it was intended to work? And, what is the practical effect of this?
Celestias do Supreme Good damage (3-18). Is all that Good damage lost with a weapon effect? Or is it just that the Good damage no longer breaks Good DR? Does a target get 3-18 extra base weapon damage?
I'm going to guess that since it gets a blue slot the devs have no interest in fixing it, I just don't understand why it happened in the first place or what the practical results are when using a broken weapon (broken because buffs have been cast on it)?