Fire Emblem: Rising Thrust except enemies get stronger and tougher every few turns
This could be part of a map gimmick. Or an optional difficulty. Or an optional difficulty modifier turned on/off after choosing a difficulty level. Perhaps bosses will get this buff. Perhaps not. This code could even be used to nerf the power of the player's units every few turns. Or their growth rates. Mwahaha.
"The map gets harder over time" seems like a great way to force the player to play fast and make interesting choices to minimize damage taken with your risky dynamic playstyle instead of prolonging the map's completion for maximum EXP and WEXP gain. I don't find sending invincible juggernauts with 1-2 range weapons to eat foes alive on enemy phase interesting. My game already modifies EXP gain calculations so any unit under a map's intended level will gain a HUGE exp bonus and any unit under that map's intended level will gain a HUGE exp penalty.