Warriors to get cheaper by a point or
Maybe something like the enemy cannot beat them by more than their SCR, so say a unit of 6 knights with banner can only beat them by 1, but a fully ranked up unit can beat them by 4 or 5. Or maybe they get snake eyes on double 1 and double 2.
Bring it in line with a mage so it needs 1 to fail cast, then double 1 to kill itself. (If it was double 1, double 1 then it'd be more reliable than mages as they multi dice stuff). So 1-6 of miscast (which is probably higher than most mages) and then equal chance of topping itself to a mage, obviously need to come up with 10 other outcomes, but could have a few groups of those to minimise the number of varients.
2 Ka-Boom, anvil is now a pair of smoking boots in Warhammer. 3-4 Magic discharge, everything within 2D6 takes a S4 hit, no armour save. 5-6 Whoops wrong rune, instead of the intended rune the target unit(s) gets targetted with one of the other runes, the opponent gets to pick which one but if multiple units are hit it must apply the same rune to all.
7-9 Fizzle, nothing happens. 10-11 Rune power is converted to magical energy, opposition may cast any spell. 12 Kerzaaapp: Rune goes of as ancient power but can't be used rest of game; other runes can still be cast in future turns. Use our warhammer Online gold service will make your character stronger.