Since Glory Slash is physical, I tried it with Sneak Attack a few times. I can tell you that it does work and would indicate that Assassin's Charge and Warrior's Charge would work too.
I have not tried it with Souleater yet (I assume the effect would be the same as using Shockwave under Souleater w/ a Great Sword).









I've tried a few times, but it looks as if you can't exploit Hide in an AoE sense by forcing Sneak Attack on all. I was hoping that I could go into a large group of them, hit Sneak Attack, Assassin's Charge, and Hide prior to performing Glory Slash with the intention of making every enemy suffer the effect of Sneak Attack + Glory Slash at once regardless of position. You can tell that it seems the focused enemy is the only enemy Sneak Attack would apply to.

I have not tried SA+Souleater, TA, Last Resort, Mighty Strikes, or Souleater alone.

I do not know what Building Flourish would do to this weaponskill or which stat it is based off of yet.

I have not been able to use modifiers like the Soldier's Drink yet, but I can try a /MNK multiboost to see if it has any effect.

Edit - Here's a MNK Multiboost. The difference isn't too great.

Arch could make golf interesting! Good stuff.