I haven't had much luck in getting ⭐⭐⭐⭐ heroes of other seasons. So far I only have 1 Atlantis, 2 Valhalla, and 1 Sand empire. ⭐⭐⭐ I have plenty of them. So currently I am upgrading these heroes costume which I have already maxed the original. I have fed Skittleskull to a ⭐⭐⭐⭐⭐ green by the way because:
1. slow mana
2. only cause enemy dizziness
3. I have Little John, which although slow mana, he can delay enemy mana fill (I should have chosen to max him instead of Skittleskull then😅😅)
And also I am thinking of maxing Melendor instead of Kasshrek, especially that Melendor in costume boosts defense, an addition to his original skills.