jaunty python
Despite being much rarer, the Illuvials Holo and Dark Holo are the same as the rest, the difference is only aesthetic. This means that they do not have the value they should, and that it is not as exciting as it should be to encounter them. Also, it is likely that you will decide not to capture them, or if you do capture them you will end up not using them because it is difficult to find one with good statistics. What I propose is something that gives them more value without creating an abusive pay to win.
The idea is that these Illuvials have better statistics on average than normal Illuvials, and also have a higher level. In the case of the Dark Holo, much better average statistics and a much higher level. To compensate the normal illuvials could have worse statistics on average. This should give them that extra value that they should have due to their greater rarity, without forcing players to have to get Illuvial Holo or Dark Holo, since the normal ones can also end up being obtained with good statistics, and they can be raised to the same levels.