Which monster do you like the most in Heroes 5 (level 4)?

Vayshan, the conversion of young units into seasoned ones (I haven't checked this in version 1.0 for a while) costs x-y, where x is the price of a seasoned unit and y is the price of a young unit. Therefore, the player doesn't overpay for the conversion. However, with patches and add-ons, the developers might have introduced some changes.