While looking up ninjas that can buff Susanoo Itachi (who falls under male, konoha, uchiha, akatsuki, blood limit, secret jutsu user, fire attributes) for GNW and Ranked Battle, I decided to create a list of all the ninjas and what they buff exactly:

Attribute Buffers:

Konan : 30% attack and ninjutsu buff + shield based on 40% of her resistance for all Akatsuki ninjas

Fire Main: 40% attack and ninjutsu buff for 3 fire ninjas OR 40% ninjutsu/combo rate for all secret jutsu users

Earth main - 30% tai/nin if shielded

Earth main - 40% combo / 25% atk if male

Wind main - 40% nin/res if in the same row

Lightning Main: 25% attack buff and heal for all ninjas in your line up

Guy: 30% attack buff for all ninjas in your line up + 15% heal on taijutsu dmg

Hashirama: 30% ninjutsu buff for all ninjas

Tobirama: 30% attack buff for all ninjas

Sarutobi and Minato: 40% resistance buff for all ninjas

Iruka: 30% attack and ninjutsu buff + shield based on 50% of his resistance for all Konoha ninjas.

Asuma WB/Edo Tensei: Units with full health will have their attack and ninjutsu buffed (30% i believe for both attributes, correct me if im wrong)

Ino GNW: 30% attack and ninjutsu buff for all secret jutsu users

Shikamaru Make-out Paradise: 100% defense and resistance buff for secret jutsu users

Madara Uchiha: 20% attack and ninjutsu buff for Konoha ninjas

Barrier Buffers:

Anko: 40% Attack and Ninjutsu buff for fire ninjas

Danzo: 40% Attack and Ninjutsu buff for fire and lightning ninjas

Shisui: 40% Attack and Ninjutsu buff for fire, lightning, and wind ninjas

Onoki:40% Attack and Ninjutsu buff for fire, earth, and wind ninjas

Mei Terumi: 40% Attack and Ninjutsu buff for fire and water ninjas

Suggested Teams:

Fire Main: X - Shisui - Itachi OR X - Shisui - Itachi

--------------Main - Killer Bee - X -----Main - Iruka/WB Asuma - X

Earth Main: Asuma/Iruka - Itachi - X

----------------Main - Shisui - X

(Shisui can be replaced with other barrier ninjas, but as of now he's the best barrier ninja to be paired with Itachi)

If I've missed any ninja please or have a team you'd like to share let me know in the comments

Thanks to everyone who helped me make corrections and suggested teams!