Omni-Weapon Proficiency: Iihiko's proof of worth. He can use almost any object in the enviroment as a weapon, and use it to an incredibly effective degree. He was able to pick up Zenkichi's glasses, and use it with such skill that he was able to match Medaka in close combat. He can use the air itself as a weapon, or grab a still living person on the battle field and use them with almost perfect skill. He managed to take a rubber band, and bisect Ajimu in a single shot. His ability to wield almost anything as a weapon is tied in with his other ability, Irreversible Destruction, as all of them take on the same properties, with almost all of them seemingly bypass durability. How he chooses his weapons is not clear and seemingly arbitrary to an on looker, but he can apparently distinguish the most effective weapon for the given situation, and find which tool is most compatible with his powers.
Subjective Immunity: That which Iihiko does not recognize, does not effect him. While Iihiko is incredibly durable, that is not what makes him so hard to kill. It is the combination of the defensive aspect of Irreversible Destruction and this ability that makes him borderline invincible. Making Iihiko recognize attacks is incredibly difficult. When kicked in the face, he perceived it as nothing more than a mosquito bite. Even if an attack is powerful enough to damage him, it does not mean it will effect him. He was stabbed full of swords, but perceived it as no more than acupuncture, so he took no meaningful damage despite the sword sticking into him. He was struck with massive bolts of electricity, but he perceived it as nothing more "Low Grade Electra-Shock Therapy," so it dealt no damage and only managed to relax him. He does not seem to recognize Abnormalities or Minuses at all, and as such he is not effected by them. It is unclear if it is a product of this ability or Irreversible Destruction, but he can also seemingly ignore defensive abilities that he does not recognize as well. If one can manage to make Iihiko recognize an attack, then he must defend. However, an enemy may be better off if he did not recognize their techniques to begin with, as the alternative can be far worse.
Irreversible Destruction: Any damage Iihiko deals to the world does not heal; Shiranui states he was a man born to destroy the world. Whether natural or skill based, Iihiko's actions cannot be recovered from. That includes even unconventional ways of healing such as Kumagawa’s All Fiction. However, the true horror of this ability manifests itself in the defensive application; the stronger an attack used against him, the further the attack itself will be "broken", and never return to normal. An arm used to punch him will be permanently broken, and superpowers will often become unusable. He will also no longer recognize any ability or technique previously used against him as an attack, so even if the power is somehow still functional after being used on him, it will not effect him anyway. However, if Iihiko is defeated, then the damage will become reparable.
Supernatural Luck: All Abnormals have this to an extent, but due to his "Hero" status, Iihiko dwarfs theirs by a vast margin, despite not being an Abnormal himself. Another "Hero," Medaka, is capable of easily manifesting one in a million chances and guessed the next combination of the door which has a 1 in a trillion chance of happening, stated to be able to pull it off a million times in a row, far superior to all other abnormals who pass through the same door on a daily basis, causing all dice she rolls to stack on top of each other and helping her to win elections. Heroes can have enemy's attacks miss vital areas, be spared by the whim of enemies, and come up with winning strategies in a pinch. The world revolves around them, causing events to flow somewhat analogous to a narrative, with Iihiko's version being most similar to that of a classical Fairy Tale. However, as a Fairy Tale "Hero," Iihiko can lose this status by performing sufficiently 'unheroic' deeds.
Possession: Upon Iihiko's death, he can transfer his consciousness and abilities into the body of a fully-prepared or in-training Shiranui village backup. However, this is more of a function of Shiranui Village wanting to preserve unusual existences like Iihiko, Shiranui Village could end up wanting to preserve someone else or not wanting to preserve anyone, depending on the circumstances around Iihiko. On top of this, if there aren't any suitable backups prepared, he likely wouldn't be able to possess anyone.
Rules: cosmology/speed equal