Kuma, Vegapunk and Bonney because the void century history is written in the bible.
Clover, Robin, Olivia and Ohara scholars who were researching Void Century, as well as Saul and Dragon.
Loki and the giants royal family who problably are way more connected to the void century than all other races.
Kureha and Hilululuk if they really are tied to Rocks D Xebec.
Crocodile, Teach, Lafitte, Mingo, Enel and perhaps King and Urouge