Flowing Black Silk Sash  

What does this hasten? Basic physical attacks, combat skill attacks, offensive spells, defensive spells, Everything the character does in combat?

As of the CU13 and Desert of Flames the haste from items no longer stack. Only one haste item will grant haste now and its supposed to be whichever item gives the most haste. There are three types of haste now: Item Haste, Proc Haste, and Spell Line Haste. Item haste does not stack with item haste, proc haste will not stack with other proc hastes, but spell haste will stack with any other spell haste not in the same line.

Monks for example can have one item haste, one proc haste, then all three of their haste lines active at once (offensive stance, group haste, and self haste with hitpoint drain).

Max haste is now 100% too, so hitting that cap just got a little too easy.

15% haste - I was told it does stack with other haste items in game, such as the Ancient Slayer rings.

Luniae is talking about the ring of the Ancient Slayer of (insert attribute) that drops in I thinkts Codemned Catacombs...or something like that.

How many times are you going to say New in your post? *points down

yes it did ....says quest reward