Haoshoku Haki Users:
Roger --- Signature Attack Copied by Shanks
Luffy --- Signature Attack Copied by Bonney
Garp --- Signature Attack Copied by Koby
Kaidou --- Signature Attacks Copied by Momo + Yamato
Whitebeard --- Signature Attacks Copied by Blackbeard + Weevil (Most Probably)
Ace --- Signature Attack Copied by Sabo
Oden --- Signature Attack Copied by Scabbards (Mainly Kin'emon)
Chinjao --- Signature Attack Copied by Sai
Assuming those who are neither Old Legends nor have Adv. CoC won't get their Attacks Copied
This leaves us with:
Rayleigh --- Loading
Sengoku --- Loading
Big Mom --- Loading
Zoro --- Loading