I believe this would only be feasible for Greek heroes, but it'd be a nice touch. What I'm talking about is a special attack for a Hero unit that is performed exclusively against a specific unit. Heracles, for example, killed both the Nemean Lion and the Hydra during his Twelve Labors...his performance against these two units should reflect this in some manner, I believe. I mean, yeah, he already does bonus damage to MU's, but he should absolutely trouce these two creatures, and he should do it in style. Such as tackling and strangling the Lion...I can't remember how he whacked the Hydra, but I know he didn't stand there and beat on it with his club. I just feel this would be a nice touch and add some more personality and usability to the oft-overlooked Greek heroes.
Other counters would be:
Bellerophon vs. Chimera (spear down the throat)
Perseus vs. Medusa (decapitating her, not turning her to stone)
Theseus vs. Minotaur (leap on top of it and stabby stabberton)
Also interesting...Odysseus vs. Polyphemus? Obviously staying true to Homer in this case would be silly, but maybe the O-Man could bust a flaming arrow in Poly's eye or something...who knows.
This all has been hypothesized because I am bored as hell. Discuss.