User blog comment:Ikmeos/Demonic power level, powerful weapons and the primordial siblings./@comment-26982641-20170227205414

A) Special Children are the best weapon against demons. Sam never had chance to kill a Prince, but he possibly could kill them and the Knights (excluding Cain and Dean). His powers are against the demon kind, he cannot do any damage to any angel. Other special children could even summon and control demonic beings such as an Acheri. It was never revealed that if an demonic entity is immune to Sam's powers so we can safely assume that he can do lasting damage to all.

B) Colt can kill all types of demons apparently (besides Cain and Dean). They never mentioned that Abaddon could be killed by it but she is weaker than Princes and White eyed demons. We can say that she may be killed by it since the Colt can even kill the strongest demons. About angels, it can most likely kill them but it was never proven. Castiel said that if there is one thing that could kill Lucifer, it would be the Colt. However it is unclear that if it could do any damage to any type of angel.

C) First Blade can kill anything. It has a direct bound with the Darkness. Even Metatron could be killed by it when he was powered up by Angel Tablet. We don't know what would happen if we stab God and the Horsemen with it but besides that, it can certainly killed the lesser creatures.

D) Lucifer's Spear is even more powerful than Colt. It can kill both angels and demons doesn't matter their strength.

E) Death's Scythe>The First Blade>Archangel Blade>Michael's Spear>Colt>Angel Blade=Angel Sword>Special Children>Ruby's Knife. Death's Scythe can kill anything even Death so it ranks first. First Blade's effect on Horsemen is unclear and it requires Mark to work so Death's Scythe is better. Archangel Blade can instantly kill an archangel unlike Michael's Spear. Colt can kill a Prince of Hell but an angel blade can't. Special Children only works against demons. About Lucifer's Spear, we don't know any of it's properties besides it can pierce a weakened Amara's skin unlike Earthly weapons.

F) Eve and Leviathans are a mystery. Death's Scythe could definetely kill them and I think First Blade can kill them. However it is never revealed that the First Blade could kill Leviathans or Eve.

G) Horsemen's powers have a level difference. Death is much stronger than Archangels but we cannot say the same thing about Pestilence. Pestilence could affect Earthly beings. He was surprised when he could affect a nearly human Castiel. All we know is that they could be killed by Death's Scythe. Not sure about First Blade.