1. Offer 3 characters

2. For each character, do the following:
- Get all characters with lower or equal weight (ie. better or equal characters)
- Pick one of the better or equal characters based on their weight
- add the picked character to the pool
- do the same for the rarity

3. Pick one of the 3 characters

4. Pick one of the 3 rarities

5. Create a new character with the picked character and rarity

6. Pick ivs from input characters or random

7. Give the new character xp based on the average xp of the 3 characters