Viathan's Skill Point
Go up on top of the plateau, which is easiest from the south. You’ll find a Hylek with a poison gun. Fight him and win for the skill. Have condition removal and dodges thanks to the poison shooting at you but concentrate your attacks on the Hylek.
See the screenshot. There is no hyleks on the plateau.
Upd.
Done this SP on another server. On Piken Square this Skill Point bugged.
Close. ty all
This skill point is in the exact same place it was before the tower so your guide isn’t outdated. It is as it always was.
Your post had me curious about the bug though, since I did this on an alt a couple weeks ago as did a guild mate for their map completion. I decided to visit again on my lvl 37 thief to check it out and I was able to find the hylek and turret, unsullied, and complete the skill point.
It’s not bugged right now on Fort Aspenwood. If it is in fact bugged it may only be on your server. If Piken Square wasn’t an EU server I would say guest over here and try it again.
Here’s a screen shot of me finishing the skill point just minutes ago:
Maybe that Toxic Bulwark killed him and you were there before he respawned?