flawed argument

^^^ This.

Because he knows that he knows everything. therefore since he knows he knows everything he knows there can not be anything in category B.

The argument presented is really just saying the same thing over and over again

But he can only base this on His knowledge. How does He know if His knowledge truly consists of everything?

You're right about the repetition though.

Yes and his knowledge, by definition, consists of knowing everything.

Therefore, by definition, he knows there is nothing that he doesn't know.

There is a given. And that given is the being knows everything. All you are saying is "but how does he know" ...welll he knows by definition

Just because there is a definition that states something, doesn't mean that something isn't a contradiction.

For example, I could create a word called "Quadratriangle." And I could say a quadratriangle is a traingle with four sides.

Obviously, that's a contradictory idea. And just because there's a definition doesn't mean it's not contradictory.

That's what I'm getting at with omniscience. I'm trying to question whether being omnniscient is even possible. So you can't say something is not contradictory because it has a definition.

And the problem with omniscience is: a being cannot use it's knowledge to prove that it's knowledge is infinite.

wow, I sure did type a lot of fluff in the OP.

Sentence 1:What doesn't it know? When did I agree it didn't know something?

Second sentence: omniscient would be based facts as it's to know 100 percent truth of everything so he would again by very defintion know his own knowledge is true. "and a being cannot know if His knowledge covers everything that exists" Wait what tell how this is true statement tell how an omniscient being wouldn't know this? This just came out of nowhere without backing. 

"He may think he knows everything"

Why is this a true statement? Is this again a claim you gave no reason why it's true.

5th sentence: By omniscient is the idea of a being or something not having something beyond his knowledge as he knows EVERYTHING so how does this work? If you know everything then it follows there is nothing beyond your knowledge. Again this downplaying the omniscient. There is no beyond peak of knowledge because it would be incoherent for that to be true because both can't be true.

Rest of paragraph one:

He could prove to itself that it's true by the very fact of the defintion of omniscients if omniscient is true and it has it then he knows what knows is true. Again omniscient can't know be fused if he is omniscient being because he is omniscient being. The only way this argument can work if we assume he isn't omniscient which defeats the point of the argument since it was never omniscient being.

Paragraph 2: Already deal with this with my previous replies in this post and others. Again this assumes an omniscient isn't a omniscient being as if he was omniscient being it wouldn't be a question he would know regardless of the question unless it's just incoherent.

Paragraph 3: Omniscient is a state of being  or nature it's not a thought so if the being is an omniscient then it's not a question if it isn't then he wouldn't by defintion. The rest I covered already.

Paragraph 4: ^ that basically. It's a state of being.  It's not thought. it doesn't think it's omniscient it has to be omniscient being. You're confusing something believing there omniscient and being an omniscient being. The arguement is can an omniscient be omniscient which I pointed out is very possible.