Well instead of random internetsources, lets check out the latest tierlist! This one is from Tougeki Damashii, Vol5. which is somelike the top fightinggame-related magazine in japan.
A-tier
Sion, Akiha Tohno, AkaAkiha
Kouma, Ciel, Ren
A/B-tier
Hisui, M.Hisui
B-tier
Arcueid, Warcueid
V.Sion, Kohaku, KohaHisu
Tohno Shiki, Nanaya Shiki
Warachia, Nero Chaos
Miyako, Satsuki
Aoko, W.Ren
C-tier
NecoArc, NecoArc Chaos
(they also explain the ranking, but that is something for another time and another post)
Also in the Tougeki-magazine, Yukinose writes about Tohno Akiha (combos, gameplay etc), SII writes about Arc, Info 'bout NecoChaos and White Ren, and VerB2-framedata!
But anyways, that is the first 'reliable' tierlist for VerB2. Enjoy