How would gaze of two minds work in combat?

[holywhippet]

So this warlock ability lets you see through the senses of another humanoid while your own senses are turned off. What would happen if you tried to use this in combat, say to see through the sense of someone with truesight because there is an invisible enemy around. If you tried to attack with this ability in place would you attack as normal (since you can "see" the enemy) or with disadvantage since you are attacking using someone elses point of view?

[Galithar]

At my table I would rule that you attack as normal if the person who's senses you were using could also see your own character as well as the target. Kind of a need to know where you're starting to get to where you're going idea.

If they can only see the target I would say disadvantage most likely. Possibly not even be able to attack depending on why they can't see you but can see your target.

[Lunali]

I would treat it as disadvantage, but you would know the target's location. Without knowing the target's location, I'd make you guess and have you roll, only considering it a hit if you both hit and attacked a location/direction that would work.