this ninjas will exist soon on the german and UK/US servers:

Hiashi Hyuga

Hagane Kotestu

Kabuto (Halloween)

Kushina (X-mas)

Minato (X-mas)

Hayate Gekko

Sai (New Year)

Suigetsu (Team Taka)

Karin (Team Taka)

Yuugao Uzuki

Mabui (Kimono)

Lee (drunken)

Jugo (Team Taka)

Ashura (newest Ninja since 22.April 2020 on the China Servers)

Hidan (Akatsuki beginning)

Kakuzu (Akatsuki beginning)

and this Ninjas maybe come soon too or are confirmed in development for China servers:

Udon (Halloween)

Moegi (Halloween)

Konohamaru (Halloween)

Hinata (Weddig Dress)

Hidan (Akatsuki beginning)

Kakuzu (Akatsuki beginning)

Kakuzu (Edo Tensei)

Shizune (Fairydress)

Rin

Kaguya

Kinshiki

Momoshiki