Order of the Frozen Skull (Rogue archetype)

[Grynning]

My buddy Rob made a neat Rogue that makes magic ice shanks, give it a gander:
http://forgotmydice.com/index.php/2015/12/07/the-order-of-the-frozen-skull/

[JNAProductions]

Mark of the Frozen Skull is too much. Not only is it usable every short rest, it's an extra 4d6 damage on every attack. That's 8d6 for a TWF rogue (12d6 with Haste, but that's an outlier). That's a ridiculous boss killer.

[Dralnu]

Everything leading up to 17th level is on the weak/boring side, and then 17th level is too much. The power needs to be distributed better.

It also doesn't seem to have a niche. We already have an Assassin subclass and it performs its job admirably. I think it needs to be more creative with its ice / necrotic themes to stand out more. Chill of the Grave is neat, more of that stuff please.