My attempt to make Sub viableFollow

If anything, you gimped Sub by nerfing Serrated Blades.

5% damage isn't much, though ignoring 45% of your opponents' resilience would be nice.

Not really enough of a buff to make me want to go Sub over combat, though.

To fix the Sub tree, the biggest thing I'd do would be to change the number of points required for some talents. There are a lot of 5 pointers that you really need to have, so your choices become quite limited when you start to branch out of the tree. Here's my opinion on what they should do.

Camouflage: Remove it, combine with MoD, replace it with something that reduces the chance you'll be removed from stealth by a max of 25% or something like that.

Initiative: Up the chance to 33/66/100%.

Prep: For the love of god put Cloak and Blind back on there. We're already the least survivable class in Arena, throw us a ******* bone for Christ's sake.

Master of Subtlety: Add a Resilience ignore effect. Give us our burst back in PvP so we can be of use before we get focus fired and controlled into oblivion.

Deadliness: Add a Resilience ignore effect. Give us a reason to go past prep for PvP.

Enveloping Shadows: Remove this crap or make it useful somehow. Hardly anything in this tree has any synergy, and this is about as far from useful as I can think of. Make it a snare/stun/fear resist or something.

Shadowstep: Increase movement speed while in stealth by 100% for 5 seconds and add a combo point. With that, at least it will be useful for people that are moving.