I enjoy playing into the light spells vs. darkness spells arms race. For me an operative part of the darkness spell is:
If any of this spell's area overlaps with an area of light created by a spell of 2nd level or lower, the spell that created the light is dispelled.
That language makes it clear to me that it's a simple comparison of spell level to see who wins. Darkness is a 2nd level spell. Eldritch Blast is a cantrip. Darkness wins. You need 3rd level Daylight to counter Darkness (and Darkness upcast with a 4th level slot to counter Daylight, etc.).
right now I'm playing drakkenheim campaign playing as cosmic warlock, where in 6th level it gain a feature like this :
Once per turn when you miss a creature with eldritch blast, the beam returns to you as an orbiting comet around your head.
As long as you have comets, you glow with bright light out to 20 feet, and dim light for an additional 10 feet.
how does this feature interact with darkness spell
RAW nonmagical light can't illuminate it darkness and there's no mention that this feature emit magical light.
I enjoy playing into the light spells vs. darkness spells arms race. For me an operative part of the darkness spell is:
That language makes it clear to me that it's a simple comparison of spell level to see who wins. Darkness is a 2nd level spell. Eldritch Blast is a cantrip. Darkness wins. You need 3rd level Daylight to counter Darkness (and Darkness upcast with a 4th level slot to counter Daylight, etc.).
The area of light isn't created by eldritch blast but by a Warlock feature.
That's a fair observation, yet it's also the case that the feature has an interaction with the cantrip and for ease I'd take that into account.