If it's like the rank 25 dungeon, loot won't come from the ogre or the boss but from a chest at the end.

Here are the loot i know from the rank 25 dungeon.

North room boss(forgot it's name): Charred Axe(Rank 30 axe)
East Room boss(again forgot it's name >.<) : Tenfinger Tallstaff(rank 30 thaumaturge staff) and Ascetic's Tights(rank 30 DoM pants)
South Room boss(name's Antares if i remember correctly): Unbreakable Knuckles(Rank 30 pugilist weapon) and Poacher's Hat(rank 30 DoW hat)

I don't know if the item gotten from the chest go with the boss so i choose to indicate in what room it was gotten just in case.