There are currently six types, though I plan to add more (I think there will be nine in total), but so far there are the following types: water, fire, grass, ice, poison, and ground.

And there are five roles, which indicate their "battle" style.

debuffers: reduce enemy stats, manipulate the terrain to gain an advantage
healers: They boost the team's stats and are more agile in combat
Offensive: Focused on dealing damage
Mage: Unique combat style
Defensive: Focused on withstanding damage

I'm planning to hold a battle tournament featuring all the characters from everyone who commissions an YCH Card RPG. The details are in my previous post. The runners-up will win an illustration for a Telegram sticker, and the winner will receive a special illustration.