For those that have played the previous TES games, you may remember the 'Frenzy' spell. If you casted it on a vulnerable enough target (which was decided upon by levels), that target would go into a frenzy and begin attacking everything it saw, whether it was friend or foe.

My suggestion is to implement a 'Frenzy' spell in the Spellcrafting system. This spell would be a soft CC, meaning it wouldn't be stopped by Immovable, that would make the target spam random abilities on their bar. During the duration of the CC, friendly fire would be turned on for the target, meaning the target can hit and get hit by skills casted by allies. The target would be unable to switch bars or stop until the CC broke.

The CC would be, at it's core, single target with a somewhat long range, long enough to be casted from a keep wall onto a unfortunate zerg member below. The ultimate version of Frenzy would cap out at 3 targets, and be a ranged AOE. The CC would have a 3 second immunity upon breaking it, like other CC effects currently in the game.

The Frenzy spell would be a high costing spell used mainly for zergbreaking, and should not be as effective in smaller scale combat.

The idea of a Frenzy spell is to discourage 'turtling' or 'stacking' by having the threat of your friend's Impulse spam being turned against you and your group.

Frenzy would need a counter. Along with the implementation of Frenzy, Courage spells would also be added. In past TES games, Courage spells could be cast on targets to buff their health and stamina and to prevent them from fleeing. In ESO, Courage could be used as a temporary buff, cast onto just you or your small group, that would prevent you from being Frenzied. Courage spells would need to have a small target cap, and ultimately be more effective in small groups than in large ones. This allows small groups to be mostly immune to a very powerful CC, while making large zergs highly vulnerable to it.

I suggest these spells be added in if the AOE cap cannot be removed due to technical reasons. If the AOE cap can be entirely done away with without negatively impacting server performance, I encourage ZOS to do that instead of implementing Frenzy and Courage spells.