As of now, we see archer trigger-based lineups rampant in the arena and two of the reasons why is how DEF mitigates damage and how CRIT is applied BEFORE damage mitigation.
DEF blocks damage dealt by ATK almost at a rate of 1 to 1 (1 ATK damage is blocked entirely by 1 DEF), making extremely high ATK heroes (like berserker) extremely strong and popular, and medium ATK heroes significantly weaker. For example,
Berserker vs Warlord against enemy with 5k DEF
Berserker with 12.5k ATK = 12.5k - 5k = 7.5k DMG
Warlord with 8k ATK = 8k - 5k = 3k DMG
7.5k ÷ 3k = 250%
Also, CRIT multiplies damage dealt by ATK by 2 BEFORE damage mitigation is applied, making the disparity between a CRIT attack and a non-CRIT attack extremely great. For example,
CRIT attack = 5K X 2 - 4K DEF = 6K
non-CRIT attack = 5K - 4K DEF = 1K
6K ÷ 1K = 600℅
Hence, I suggest reworking DEF/Damage-reduction formula such that it mitigates a PERCENTAGR of ATK at a decreasing rate as DEF increases, instead of flat damage reduction it (partially) relies on as of now. Also, CRIT should be applied after damage mitigation is applied.