What Chris said :) I agree it would be a fun visual, but unfortunately it comes with a few mechanical, lore and story concerns. For example, if MC can clone himself:
1. It turns all combat encounters into easy mode (he can just manifest a small army at will)
2. He would use them for tactical reconnaissance and ambushes, functionally removing any chance of anyone ambushing him (he would have left a few hidden outside the church just in case, which would have completely changed the finale)
3. He would use them to swarm across the warmap, capturing six territories at once and leaving the opposing factions absolutely reeling.
4. He would almost certainly trick everyone into believing that one of the clones was the "real" MC and then hide so he could keep generating more versions of himself in safety whilst the clones took all the risks.
5. He would have left a few in the Council demesnes too.
6. Given all the above, I would have to keep changing perspectives and scenes and give players the ability to jump to different clones.
Even if I give him weaknesses - such as the clone power is diminished, or they can't use powers, or there's a maximum range, it is still a massively overpowered ability because it's external to other people. Currently MC is limited in that his powers are used on others, so if they're protected, or mentally strong, he's in trouble... the strength of a clone is not affected by other people, though.
Finally, it would turn the game from a mind control game to a shadow clone game, as in Act Three it's an infinitely more useful ability than Awaken or Shatter :P
There's a reason Naruto used it all the freaking time ;)
(Oh, and to anyone who's thinking "but Sawano can do all those things!"... yes. Yes, she can. Makes you think, doesn't it..?)