This build does have its problems. WARNING WALL OF TEXT INCOMING!

OK, this is still slightly unfinished and it is a bit of a one trick pony to coin the phrase of a few others on these forums. This is built around the HK SAB Synergy crystal's 4 pt ability.
the rotation itself is slightly more difficult than a normal sabdancer and is 16 seconds long.
There is what i call dead space in the rotation, a set of 3 attacks that could be better optimized. And perhaps needs a longer look at moving a few things around. It also is positional.

The idea behind the build is this: concentrate all of your big guns into less than 6 seconds of time to take full advantage of the synergy crystal bonus. effectively this gives you a full set of 15 second spike charges, a backstab, 16 seconds worth of Puncture and a Precision strike all with the full bonus of deadly strike and the bonus from the synergy crystal. every 30 seconds.

The current sabdancer build will only take advantage of 1 set of charges for the 4 pt Sab Synergy Crystal. even though the damage bonus works for 6 seconds... its not enough time to put in another full set of charges.

here is the rotation (be gentle I know the first three strikes are not huge dps...but the rest should make up for it I'm hoping)

3x Savage strike, 2x spike (deadly strike)
Backstab, spike charge, keen strike, spike, spike (deadly strike macro)-----Incriminate, blade tempo, trinket
Backstab, Precision Strike, Puncture, Detonate (all your big guns here with deadly Dances effect + synergy)

there is a nice little trick built into the rotation the first deadly strike uses 2 deadly dance charges for melee attacks and the 3rd is used to help set up for the Crystal bonus...and does not immediately use this bonus.

Backstab and keenstike each will use 2 of the 3 deadly dance charges the third gives the : (next set of charges will get 105% buff) this buff lasts for 9 seconds and is not overwritten by the 2nd deadly dance....what this does, is allow you to get the deadly dance bonus for 3 attacks in a row and an entire stack of charges. with the incriminate synergy bonus on top of this bonus every 32 seconds (because the rotation is 16 sec long)

for simplicity i used 3 savage strikes to start off the rotation but you could replace this with keen strike, quick strike savage strike... you cant use another back stab as that would increase the rotation to be to long. 18 sec instead of 16 and i wanted to keep it as close to 15 seconds(the length of the spike timer) as possible. But these three attacks that start are definitely the weak point in the rotation....

I was unable to get anyone to help me with this on the test shard so i couldn't try it out getting the incriminate bonus. So no parses as of yet... just parsing this against the standard sabdancer is roughly a 1-150 dps loss I am expecting to get that back and more with the crystals effect (although i could be wrong)

i am open to any and all ideas to improve this build. bring on the comments tell me what you think. Be kind.