Got this for my bard because I cant always use vainglorious shout and also it would be nice to have a 14 min debuff. It is supposed to debuff MR by 83 (at L75). Tested on another player in a duel and it isnt giving -83 MR, its only giving 60. I dont think it could be a pvp reduction because I also tested boastful bellow which is supposed to give 50 debuff and does. I guess its still worth using since they stack, but Im feeling a bit cheated that I didnt get the debuff I expected from it.
It's supposed to give -60. So it's doing 100% of what it's supposed to. http://spells.eqresource.com/spells.php?id=10608