Prowler(night) & Champion(day): 0
Artemas(night) & Apollo(day): 0
Midnight(night) & Day(day): 0
Dusky(night) & Altair(day)
Others:

My edit:
So these are just the names I found and liked
Info:
1.they are both villains cause Im just like that-2.Night is brawn day is brains 3. both go by he/they/it 4. they aint biologically related even though it looks like it-(I tried T-T) 5. They both a have human-level intelligence