I always wondered why Eros ended up as such an ineffectual character in Starlin's stories. The whole Eros/Thanos naming scheme is a big Freud reference to the opposition of the sex drive and the death drive. In theory, Eros is a balance for Thanos. I wonder if Starlin just couldn't make a swinger superhero work, or what?
Speaking of Eros, his whole "love power" is another post-Starlin idea. Starlin just showed Eros as a happy-go-lucky/happily-get-lucky type with some generic super-strength. Also, Mentor seems like kind of a crappy father, doesn't he? One of his sons turns out to be a genocidal or omnicidal maniac, the other is a hedonistic slacker with the world's creepiest super-power.
In fairness to Mentor, the other million or so kids he has turned out just fine.