Well, I wouldn't resume a development but rather I would want a proper remake in a well done way, there is one game in which I liked the concept itself (Harem wars), basically defeat enemies and increase your harem or be defeated and lose harem members.
What I would have liked to do in that game is:
-First change genre, from RPG to SRPG, I would rather have it made with SRPG studio so that it had a somewhat fire emblem style combat.
-Second I would add a territory map for resources that would let you buy units and stuff, enemies being able to attack your territory and take over...
-Third adding some strategies, like raids that weaken the defense on a territory and are harder to defend but can't capture your characters.
-Fourth a mechanic related to chance of capture, when a character is defeated there is a basic chance to capture her, increased by ally traits, strategies and other elements to become a fairly good chance.
...
There are many systems that I would also want like a rescue system and a lot more stuff but overall the concept is just that, a SRPG in which the MC wants to conquer all rivals and have a big harem.