Homm 5 in QHD 21:9
I think academy in homm5 tribes of the east are very strong. The correct selection of artifacts and the use of amulets makes the opponent's moves impossible and completely useless, even at the "master" level. For amulets, it is enough to take perk1-initiative, perk2-protection from magic (For creatures without magic protection, otherwise a perk with hp or with a fighting spirit) and perk3-luck. The power of the amulet primarily depends on "knowledge", which gives just crazy bonuses from the initial amulet on the hero without leveling up.
In addition, the ring of speed and initiative 20% + 10% and the staff of Orson (-20% to the enemy's initiative) and you become simply invincible even at level 25. To finish off the effect, you can try to collect a set of gnomes (A full set gives 2 spells at the beginning of the battle, I think this is an overly imbalanced set for protection).
Mods: Epic war age.