To reproduce:
- Go into stealth
- Cast Tricks of the Trade on Brann (or other? Have only tested with Brann)
- Ambush target
- Watch in sadness as Deathstalker’s mark does not apply, or applies and then immediately falls off.
If I ambush from stealth and then use tricks of the trade as me second ability, Dealthstalker’s Mark acts as expected and stays on the target.