Here, you can try using and upgrading all the heroes without any worries. There is a fighter rebirth function to return ALL resources that you used. So feel free to use any resources to power up your fighters. Never be afraid of training your heroes wrongly as a newbie here. Just enjoy the game and build what you want to try.
Guides
Legend of Kingdoms: Idle RPG – Tier List Guide (From Early to Late Game)
This is my personal tier list based on using/going against these characters as well as their abilities from early to late game in PvE and PvB (Player versus bosses). Guide […]