Appearance
Sengoku is tall, broad-shouldered, and muscular man with a fair skin, long braided beard, and a mustache. He is usually seen with his pet goat. Most of the time, he wears glasses and a full Marine admiral uniform that's adorned with medals. The most distinctive feature of this uniform is a life-size seagull on top of his cap, and his huge Marine coat, which he wears like a cape. His cap usually covers his hair, which is an afro. When he uses his powers, his hat is usually off revealing his afro. Despite being in his mid-to-late seventies, Sengoku retained the appearance of a much younger man, with his hair color not turning gray for 20 years. It is possible that he dyed his hair.
Twenty years before the present storyline, while Sengoku was still an admiral, he did not cover his afro and did not have a beard. He also wore a regular suit attire than he does in the present storyline, which is unlike a typical admiral's formal suit. The only Marine related attire he wore at the time apparently was his Marine coat, draped over like a cape However, when he was fighting Shiki in Marineford, he was wearing a black suit.
After the two-year timeskip, Sengoku's black hair has turned gray, and he now dresses far more casual since retirement.
Personality
He appears to be a proud man who is loyal to the World Government and never questions orders. He also won't accept any reason for letting a criminal go and also has a habit of getting very irritated with failure. From his view, the Shichibukai are just pirates , though he notes how valuable they could be when the time comes. However as years went by, he appears to be losing his faith in the Government, shown after the Whitebeard war he was angry at the order from the Government that there was to be no bounty on the Blackbeard pirates to cover up the shame, thus placing nations in danger. He has shown his ruthlessness, during the War, when he transformed into a giant Buddha, to attack Luffy, M. 3 lives were in vain, trying to save Portgas D. Ace and when the Blackbeard Pirates attempted to destroy Marineford and nearly succeeding in destroying the Blackbeard Pirates.
As of lately, it would seem that he has become concerned over the movements of the Luffy and his crew , and has followed their movements ever since leaving water 7 , though his current concern is about the upcoming war against Whitebeard , to the point that he brushed off the incident of the attack of a to the admirals . Upon hearing Luffy's break-in of impel down, Sengoku was so frustrated that he almost took it out on Garp, and has come lose his patience with the antics of Garp's family in general.
Sengoku also thinks and believes that a person's birth (with the consideration of the parents' reputation) is enough to determine the potential impact they could bring to the world if left unchecked, such as Ace being Roger's son, and Luffy being Dragon's son. This is shown at Ace's execution where one of the main reasons for Ace's execution was not because he was a pirate, but because he is the son of Gol D. Roger and he believes that Ace must be executed by all means even if this meant an all out war with Whitebeard.
Sengoku the Buddha may seem ironic at best, because through the course of the series he is shown to be quite capable of violence. It remarked on this irony when the Shichibukai convened at Mariejois to chose a successor for Crocodile. However, with the revelation of his Devil Fruit, it would seem his epithet's origins come from his fruit's ability, exactly like the three current admirals . He also appears to have some common sense, as shown when he ordered the Whitebeard war to be over and tend to the wounded. His sense of justice isn't as uncompromising as Akainu's; it seems to be more of a mix of both absolute and moral, as he did make a large speech about morality. He also called the war to an end upon Ace and Whitebeard's demises, after Shanks made his appearance. An another hint of Moral Justice is also shown when he was infuriated when the World Government decided to cover-up the breakout of the Impel Down prisoners released by Blackbeard, although he said once not to question the World Government.
Beneath his stern attitude, Sengoku is very kind and compassionate. When he learned about Donquixote Rosinante's death, a man he considered to be like his own son, his heart broke and drove him to tears.
Powers and Abilities
Physical abilities
Sengoku was one of the most powerful Marines of his generation, along with Garp and Tsuru. Even without his Devil Fruit powers, Sengoku possessed vast strength, enough to effortlessly hold down an enraged Garp with one hand.
Devil Fruit
Sengoku ate the "Hito Hito no Mi, Model: Daibutsu", a rarer-than-Logia Mythical Zoan-class Devil Fruit which allows him to turn into a gigantic Daibutsu, which is probably the reason for his nickname. Nearby Marines claim that they have never seen him use this power before the war.
While enlarging, his Marine jacket, glasses, and pants enlarge with him; his uniform, which also enlarges, seems to be tied around his waist, though he was not seen doing it during the transformation. The color of his body (and uniform) seems to change to a golden skin color, similar to a polished gold statue. In this form his body has different proportions, his torso and arms are much larger compared to the rest of his body.
This ability gives him a massive power boost to his already impressive strength, enough to cause the execution stand to collapse in one indirectly connecting punch, despite the combined effort of Luffy's Gear Rhird and Mr. 3's candle wall to absorb the attack. He can also launch an explosive shock wave with a palm thrust, enough to send a majority of the Blackbeard Pirates flying a fair distance. As a human, since this is a variation of the normal human Zoan fruit, he also gains a sense of enlightenment from using its power.