Mold Breaker ultimate would be awesome.
Mold Breaker is an Ability in Pokemon. For those of you that don't play it, Mold Breaker makes your attacks bypass the Abilities of the opponent. For example, there's an Ability that makes you immune to a certain damage type. But, Pokemon with Mold Breaker can still hit you with that damage type.
I, personally, would love to see something like this in League, perhaps as an ultimate. Essentially, it would allow your next (X) abilities and/or basic attacks to bypass enemy defensive buffs such as Barrier, shields (Tahm shield, Udyr Turtle Stance, etc), spell shields including Banshee's, and damage-reduction spells like Warwick's E, Jax's E, Fiora's W, Fizz's E, and maybe even things like Tryndamere ult, Kayle ult, Kindred ult, Yi ult, and Challenging Smite.
Given the power of this ult I could see it being as simple as an auto-attack reset for one attack, three attacks, whatever; something simple that would ordinarily be bound to a Q or an E but is an ultimate because of the strength of the buff. It could also just be a skillshot / targeted strike of its own, either one shot or able to be fired multiple times after first cast similarly to Evelynn's Q. If it is a single attack it would be great if it also has execute damage (as one of its primary purposes would be to finish off low-health targets using a defensive ability to possibly survive).
On the more-nerfed end of the spectrum, I suppose maybe it couldn't bypass ultimates, only spell shields / barriers / regular abilities, and on the more buffed end of the spectrum maybe it can cancel a wider variety of abilities such as Guardian Angel, Zac's passive, Anivia's passive, Sion's passive, etc.
Extreme Prejudice (R): John's next (X) autoattacks for six seconds deal an extra 100 / 150 / 200 + 50% AD physical damage, with the last attack also dealing 8% / 16% / 25% of the target's missing health. These attacks will successfully land regardless of any defensive buffs the opponent may possess, including spell shields, barriers, damage-mitigating spells, and spells preventing the user from death. Resets the auto-attack timer.
Memento Mori (R): Skillshot/targeted, range 750 units. Deals 150 / 200 / 250 + 100% AP + 8% / 16% / 25% of the target's missing health in magic damage. This spell will successfully land regardless of any defensive buffs the opponent may possess, including spell shields, barriers, damage-mitigating spells, and spells preventing the user from death.
Let me know what you guys think.
