A couple of nominations here. To fill out the rest of 5-B, first I'm nominating
Samus Aran (Legendary Suit) and
Dark Samus for a spot in 5-B above Arthas (Though I guess you can throw
Ridley in there too so it would "Characters from Metroid"). Samus has a Universe Level Technique with her "White Holes", granting her the power to one shot almost everyone in 5-B. Both characters have access to
Phazon Manipulation which posts a whole host of problems hax wise, among having many resistances to the less esoteric stuff. Samus in particular also has the 3rd best range of everyone in 5-B behind Lu and Ace, with her White Holes. Don't really know how the Metroid gang fair against Skarbrand though.
Secondly, nominating
characters from BASTARD!! for the 6th place spot.
They are already #1 on the Non Smurf list in 5-B, and I'm not really seeing anything from The Batter, Arthas, or Skarbrand (In his 5-B Key) that would be able to take them down (For resistances it says Skarbrand resists Psychic powers, but what sections of Psychic powers are unclear). Plus Angels and Demons such as
Konron have so many magic shenanigans such as Abstract Existence, Type 1 Concept Manip, High-Godly Regen and Negation among other things. However, due to the fact that they are Non-Smurfs, they would go below Kang Han Soo.
Lastly since the Unknown section is being filled out, nominating
Lumina from Final Fantasy XIII above Yue. She's got access to
Unseen Chaos Physiology which grant her a bunch of powers that come from a Non-Existent source. The power of
The Crystals which grant Negation of a bunch of Immortalities and High-Godly Regen among doing a boatload of other things, as well having access to summons who can fight against
2-A Level Characters.