Ok this is COMPLETELY ORIGINAL 
Every monster can drop some tokens right? Some monsters drop more, some drop less. After you get like 50 or 100, you can level up to level 2 by using a trainer. Some creatures also drop different tiers of tokens. Like level 1-10 drop golden tokens, levels 10-25 drop green tokens, and 25-50 drop orange tokens. The trainers can be placed in the starting and main cities near inns or something. Vague concept but a concept all the same.
Every monster can drop some tokens right? Some monsters drop more, some drop less. After you get like 50 or 100, you can level up to level 2 by using a trainer. Some creatures also drop different tiers of tokens. Like level 1-10 drop golden tokens, levels 10-25 drop green tokens, and 25-50 drop orange tokens. The trainers can be placed in the starting and main cities near inns or something. Vague concept but a concept all the same.