Fear

[KLS]

Well of course one option is to not give players the spells. If you're willing to recompile it should be simple to remove the stun from the spell effect. Just search spell_effects.cpp for SE_Fear and comment out the Stun()

If you wanted to modify the spell file you could modify the duration without having to give the file to the players, if you added a recast however the players would somehow need to be able to have access to a new spell file or it would not show correctly.