Ok, so I'm not too certain about this but I'm pretty sure haki wasn't thought of or present until after whitebeards death, so would I be wrong too assume that of course he had it and is probably one of them most proficient in it even though it wasn't shown? Lol
After Luffy used Haoshoku, everyone was saying he was like Shanks and Whitebeard. Akainu also said that Vista and Marco were haki users when they attacked him, but were not at the level where they could hurt him, so Whitebeard being their captain and hurting him shows he had Busoshoku as well.
Logia's don't need to fully transform, Enel showed once you get to a certain level it is an automatic response. He was unprepared for Marco and Vista as well but they couldn't do enough he confirmed them as haki users.
WB stopped Kizaru as well while he was basically in his light form. If WB didn't have haki he couldn't stop Kizaru from reaching Luffy.
He obviously had haki in marineford, otherwise he couldn't have hit Akainu so brutally.
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Even you think his first strike caught him by surprise(which is not the case since he saw Whitebeard comiing), he had time to defend himself against the second strike. Infact he is the one who attacked first at that moment before Whitebeard kicked the hell out of him
And if you just want to have line confirming his haki in use, there is this where Whitebeard is mentioned to have used haki
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But somehow Aokiji managed to dodge it
But haki power is dependent on your will and Whitebeard's condition in marineford was unstable. That's why i think at times he couldn't use it as efficiently, but he still could use it
He obviously had haki in marineford, otherwise he couldn't have hit Akainu so brutally.
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Even you think his first strike caught him by surprise(which is not the case since he saw Whitebeard comiing), he had time to defend himself against the second strike. Infact he is the one who attacked first at that moment before Whitebeard kicked the hell out of him
And if you just want to have line confirming his haki in use, there is this where Whitebeard is mentioned to have used haki
You must be registered for see images
But somehow Aokiji managed to dodge it
But haki power is dependent on your will and Whitebeard's condition in marineford was unstable. That's why i think at times he couldn't use it as efficiently, but he still could use it