Mastery Bundle Questions

[ElectraLove]

So I am returning to PvE after a year so I figured I would begin by getting the Duelist Bundle for HM skills which I will do later today, however, I wanted to ask, what exactly does the Mastery Bundle do and is it worth it?

The only things  I see that I recognize are the Gems and the HM Energy. I'm not entirely sure how accessory upgrades work now. Do people upgrade the accessories given in the bundle or? 

Also, what do the rest of the mats and the bundle go towards? For context, the last time I PvP'd, I believe Shattered Masts was the latest dungeon, and I had a True Scorpio Bangle on my FM. For context, I am making a Warlock. Not continuing the weapon path on my Force Master.

[yanpower]

salvage the bangle and u will get new weapon, proceed from there. Mastery aint worth it, but duelist might help u getting secret techniques.