The bonus of the Wizard king gives targets struck in melee maximum bad luck (which is -10).
The Wizard king is most likely to learn Nobility and Order magic and fairly likely to learn the Tactics and Combat skills. Wizard kings cannot learn Chaos magic or Nature magic when leveling up unless some basic training in those skills is already known.
While maximum bad luck is a good effect to put on enemies, magicians without combat skills shouldn't enter melee. The bonus isn't good enough to put the Wizard king anywhere near the front lines.
The skills are great, though, as the larger armies Nobility gives you, can be boosted by Order magic spells.
|Heroes of Might and Magic IV classes|
|Standard hero classes||Knight - Death Knight - Lord - Thief - Archer - Barbarian - Priest - Necromancer - Mage - Sorcerer - Druid|
|Advanced classes||Archmage - Assassin - Bard - Battle mage - Beast lord - Beastmaster - Cardinal - Crusader - Dark Lord - Dark Priest - Demonologist - Enchanter - Field marshal - Fire diviner - Fireguard - General - Guildmaster - Heretic - Illusionist - Lich - Lord commander - Monk - Ninja - Paladin - Prophet - Pyromancer - Ranger - Reaver - Seer - Shadow mage - Summoner - Warden - Warlock - Warlord - Witch king - Wizard - Wizard King|