What's Ace's deal?!
Well, I actually made him explain himself pretty good over here, if you want it straight out of the fox's mouth. Otherwise, the various info tidbits and videos on this post will probably help, but please let me know if you're curious about something else. I'm always down to ramble / write more info if people are interested. Also, his entire season of Kamen Rider is free on youtube!
In fact, here's (the first version of) the OP, because I love it and you can't stop me. The 'obvious symbolism' in it happens literally in the show, including the barbed wire. And the gun to the face.
Appearance and Voice

(Sir David Attenborough voice: And here is the fox being a... sassy little shit. This is... his natural state.)
Ethnicity: Japanese this time. He's been born into lives all over the globe, we've even seen a few as adults in flashbacks, including one white guy (victorian england perhaps?) squaring up with a Desire Driver already clipped to his waist. He's had full childhoods in an unknown number of cultures without knowing who he was otherwise, first, so he's always been fully integrated wherever he ended up. This final roll of the dice, though, is Japanese.
Eyes: brown
Hair: black
Height: 183 cm (6', 0.5")
Weight: 82 kg (180 lbs)
Age: Appears as a young man in his early twenties; the appearance of his last life as a mortal human (and who he was for all but the last few episodes of the show).
Aura: If someone can sense that sort of thing, Ace is a kami and doesn't really take pains to hide that fact from supernatural senses. He's 'the fox god'. When he uses his power as the God of Creation, it manifests in white-blue light and the deep sound of church bells from thin air, just as it did for his mother.
Appearance:
All of these are clickable thumbnails!
DGP Uniform (rarely used post-canon, but you never know):

Street Clothes (examples):

He definitely favors reds/creams/neutrals, and layers.
The 'Star of the Star of the Stars' celebrity tuxedo suit:

Kamen Rider Geats - MagnumBoost (his standard combat gear):

Video shows clips from the first episode with just Magnum, then just Boost, and then the combination (with use of the Revolve On mechanic -- welcome to Kamen Rider and our casual body-horror). Ace's base form is with Magnum on top, Boost on bottom. 90% of the time if he's transformed, that's the gear he's in.
Kamen Rider Geats - Geats IX (the armor he usually uses to fight as a god, he created it right after unlocking his power):

First transformation:
(And yes, he did just re-create the world while he did it. When the tails burst out of the ground and the background becomes a world instead of a dark stage... that's why.)
How he fights in IX / uses his god powers in combat:
(Shushing his own theme music through the fourth wall was such a flex, but Ace has always been an aura-farmer.)
(Also, the guy he's fighting here was the main person who tortured his mother for two thousand years, so... the stunting was more than deserved. Not only will he kill you, but he's going to embarrass you while he does it. Sucks to suck, Suel.)
Voice:
Bonus:
This guy's commentary cracks me up. And his pew pew noises.
Well, I actually made him explain himself pretty good over here, if you want it straight out of the fox's mouth. Otherwise, the various info tidbits and videos on this post will probably help, but please let me know if you're curious about something else. I'm always down to ramble / write more info if people are interested. Also, his entire season of Kamen Rider is free on youtube!
In fact, here's (the first version of) the OP, because I love it and you can't stop me. The 'obvious symbolism' in it happens literally in the show, including the barbed wire. And the gun to the face.
Appearance and Voice

(Sir David Attenborough voice: And here is the fox being a... sassy little shit. This is... his natural state.)
Ethnicity: Japanese this time. He's been born into lives all over the globe, we've even seen a few as adults in flashbacks, including one white guy (victorian england perhaps?) squaring up with a Desire Driver already clipped to his waist. He's had full childhoods in an unknown number of cultures without knowing who he was otherwise, first, so he's always been fully integrated wherever he ended up. This final roll of the dice, though, is Japanese.
Eyes: brown
Hair: black
Height: 183 cm (6', 0.5")
Weight: 82 kg (180 lbs)
Age: Appears as a young man in his early twenties; the appearance of his last life as a mortal human (and who he was for all but the last few episodes of the show).
Aura: If someone can sense that sort of thing, Ace is a kami and doesn't really take pains to hide that fact from supernatural senses. He's 'the fox god'. When he uses his power as the God of Creation, it manifests in white-blue light and the deep sound of church bells from thin air, just as it did for his mother.
Appearance:
All of these are clickable thumbnails!
DGP Uniform (rarely used post-canon, but you never know):

Street Clothes (examples):

He definitely favors reds/creams/neutrals, and layers.
The 'Star of the Star of the Stars' celebrity tuxedo suit:

Kamen Rider Geats - MagnumBoost (his standard combat gear):

Video shows clips from the first episode with just Magnum, then just Boost, and then the combination (with use of the Revolve On mechanic -- welcome to Kamen Rider and our casual body-horror). Ace's base form is with Magnum on top, Boost on bottom. 90% of the time if he's transformed, that's the gear he's in.
Kamen Rider Geats - Geats IX (the armor he usually uses to fight as a god, he created it right after unlocking his power):

First transformation:
(And yes, he did just re-create the world while he did it. When the tails burst out of the ground and the background becomes a world instead of a dark stage... that's why.)
How he fights in IX / uses his god powers in combat:
(Shushing his own theme music through the fourth wall was such a flex, but Ace has always been an aura-farmer.)
(Also, the guy he's fighting here was the main person who tortured his mother for two thousand years, so... the stunting was more than deserved. Not only will he kill you, but he's going to embarrass you while he does it. Sucks to suck, Suel.)
Voice:
Bonus:
This guy's commentary cracks me up. And his pew pew noises.