How to level up heroes

Heroes need to upgrade their levels:

advanced stones, gold coins, experience points.

Source of gold coins:

Challenge Bosses, receive gold coins, fast raid, gold coins trial, daily tasks, on-hook earnings, voyages bounty, etc.

Source of experience points:

Challenge Bosses, fast raid, on-hook earnings, experiences trial.

Source of advanced stone:

Hero Sacrifice in the Hall of Ascension, fast raid, daily quest of emerald tower, advanced stone and gold coin trial