Khisanth the Ancient
Explorer
Petrifying Gaze: Unless surprised, a creature can avert its eyes to avoid the saving throw at the start of its turn. If the creature does so, it can't see the medusa until the start of its next turn.
Blight: Necromantic energy washes over a creature of your choice that you can see within range.
The rules are clear on this. If you're averting your eyes, you can't see the medusa. If you can't see the medusa, you can't target it with blight.
Interesting. I would have ruled the other way, because intuitively (to me) looking at the lower legs/feet but not the upper body really should work. You still see the creature, just not the face/eyes....
In a pitched battle, with people running around flinging spells and steel at each other, it would be very easy to look at the medusa's eyes BY ACCIDENT unless you turn completely away from her.
...but, yeah, that makes a lot of sense.