From my incredibly vague description, of course.
You commanded an army of (mostly) mythological critters, like Cyclopes, Hydras, and so forth. It was available, at least for the 16-bit Genesis, as a cartridge. Don’t recall if it was strictly single player, or if you could play it two player, as well.
You and the “computer player” took turns moving your units, one a time, on a map laid out with a hexagonal grid. There were various terrain types, which effected both the unit’s movement speed, and combat abilities. (Hypothetically, defending a mountainous hex from attack by a unit in grasslands/plains gave your unit a defensive bonus. But don’t quote me on that.)
Units accumulated exerience with each combat survived, and eventually “leveled up” into some more formidable version of themselves, or they simply gained in health/combat abilities with each level. Or possibly both.
(Like I said, I remember it only vaguely.)
Thinking about it further, it’s quite possible that you gained “summoning points,” or some other convention, for each castle (a single hex each) or town, or something similar, each round of combat, allowing you to bring in more reinforcements.
All that I can say definitively is that it was not Dark Wizard, released for the Sega CD. It was, however, pretty similar.
Which, of course, only helps if you remember Dark Wizard.
So, anyone got a guess? Or, a barely remembered old-school cartridge game of your own to track down?