Here are some ways to get free gems in Hero Sky (no cheats/hacks):
Nobody likes to play support, yet everbody likes to win - Bastion
In DotA2, there are basically 2 types of heroes : Carries and Supports. Carries are the heroes that have tremendous damage and can easily wipe out the other teams heroes. Supports on the other hand are the ones that help the carries eliminate the other team; be it their skills, their items or their actions. These heroes usually rely on spells ranging from disables, AoEs, damage spells, etc. These skills usually do not affect the enemy heroes anymore in the endgame.
The Gate is a role playing, real time strategy card game from Spicy Horse. It is described as "Pokemon in hell." In this game you will need to fight demon armies (in single player mode )or teams (in PvP mode.) You will need to level up your demons, upgrade their skills and stats so you can conquer both the PvE and PvP modes of the game.