I've got into this game right from the beginning, even way before it was playable and bought an alpha pack. While nowadays there aren't any alpha packs rewards anymore and probably you can only buy those, I have still played with the army quite a lot. Still, the monsters that are have (even if defaulted) seem to do quite well in battles. Fight after fight, day after day, they succeeded to advance to next level - BRONZE I.
Now, as rewards I've got the following:
- 3 BOOSTER PACKS at the end of Season 3
- 1 Legendary 2 Epic 2 Rare 3 Common monsters on the battlefield