Game is pay to win. There are levels where you need to use bronze fighters to beat it. Bronze fighters are extremely weaker than the levels require them to be. And the only way to make them stronger is to sacrifice your other fighters to upgrade them. Or you can waste time and energy grinding lower levels to upgrade them. No point in using a good combo to beat the higher levels with bronze fighters because the AIs there can instant block and counter attack you during your combos. Unbalanced game