@Piemonade, since you want a hard scramble I'll dial up my favorite 2-part challange for you.
For your Scramble, i'm going to give you a two part challange. For the first part, use a RNG to generate a number from 1-16, excluding Ghost. The resulting number will determine the type of pokemon that you receive, in alphabetical order. (Example: 1 = Bug, 2 = Dark, 3 = Dragon, etc) You must catch the first pokemon that you see that is a member of this type or that will evolve into it. Here comes the fun part: as soon as you capture this pokemon, place all other monsters into the PC except one and heal your freshly caught 'mon. You must then immediately continuously solo wild pokemon with this monster WITHOUT healing or PP restoring until it faints. The amount of pokemon that it KOs will determine the next part of your challange.
For part two, capture a Gastly in Sprout Tower after this pokemon faints. This is the spirit of your recently deceased monster. It is now an angry spirit, looking to exact revenge upon the pokemon that killed it and all others like it. As such, it must solo a number of wild pokemon corresponding to how many you KO'd with the original monster.
If the original monster KO'd 0, it must solo 30 wild pokemon of the same type as the wild monster who KO'd the first monster.
If the original monster KO'd 1-2, it must solo 25 wild pokemon of the same type as the wild monster who KO'd the first monster.
If the original monster KO'd 3-4, it must solo 20 wild pokemon of the same type as the wild monster who KO'd the first monster.
If the original monster KO'd 5+, it must solo 15 wild pokemon of the same type as the wild monster who KO'd the first monster.
Important: It must solo these wild pokemon without healing at a pokemon center, or your total will be erased and you start back from 0.
Furthermore, the amount of pokemon that you originally solo will determine the total BP of your moves.
If the original monster KO'd 0, it must have moves with a total BP that does not exceed 80, with no STAB moves.
If the original monster KO'd 1-2, it must have moves with a total BP that does not exceed 110, with STAB moves.
If the original monster KO'd 3-4, it must have moves with a total BP that does not exceed 140, with STAB moves.
If the original monster KO'd 5+, it must have moves with a total BP that does not exceed 180, with STAB moves.
If you solo the same exact pokemon as the one that KO'd the original monster, it counts as 2 for these purposes.
It must be nicknamed Vengeance.
Additionally, Vengeance cannot learn more than 1 move that does not inflict damage, so you can't load up on status moves in order to have 1 or 2 powerful attacks. Vengeance also cannot evolve, as it despises what it has become and doesn't want to move further onto the ghostly path. Finally, Vengeance must solo at least 2 of Karen's monsters, for funsies.