Is the Warlock's hex power permanent until Remove Curse is cast? That seems over-powered.
The power is effectively the bestow curse level 4 spell (reverse remove curse) once per day. So as per the spell it is permenant.
In terms of power you are getting it a few levels earlier than normal but as part of the overall package the warlock is rarely called out as a powerhouse compared to a base mage. I have personally never seen it played, but if you think it would fit your world just change it or remove it. I hope that helps.
Thanks! I might give the victim a saving throw each day to throw off the curse.