Ideas for new summoners spells

Like the title state, I want to know if you guys have though of new concept for summoner spells besides the current ones. I personally have though of two.

Last Stance: Self-Cast. Deal 40% reduced damage. Reduce all incoming damage by 40%. Berserk: Self-Target, Cast on Enemy. Becomes Taunted(silenced) by targeted champion. Deal increased 20% damage.

The first one would be aimed towards tanks, since you are basically exhausted you will be relying on your utility to be useful. Additionally the exhaust will prevent carries for taking it as surviving longer would be pointless if they deal no damage as well. Utility supports probably will use this spell as defensive probably Soraka or Janna could swap the flash for it.

The second is more of a double edge sword and could be used by any unit focused on damage . The drawback is that the self cast taunt can force you into bad positioning or bad target selection. Marksman could use it on diving units as a way to burst them down, or could be used for the divers itself (master yi or nocturne could use it effectively) or perhaps some juggernaut.

Let me know what you think? Would it be too OP, or maybe the fact that include positive and negative effects woudl make them weaker in comparison to other spells (aka, why take stance when is basically a weak barrier)