From the author's README on Thunderstore

Steezus

Super Saiyan Goku (Mid) from the PS2 game Budokai Tenkaichi 3

What's included

SSJ GOKU - full-body costume (head, hair, shirtless, pants, shoes)
Halo - A non removable halo

Features

Rigged to skate.'s character skeleton; works with normal skating and trick animations
Model and textures from BT3, re-skinned for skate.'s body so knees, hands and the shirt bend properly

Install SSJ GOKU

You need ReSkate and your own copy of skate. on Steam.

Open ReSkateLauncher.exe and go to MODS.
Search for SSJ GOKU and click install. The launcher also installs anything it depends on.
Press PLAY. In game, the MODS tab of the ReSkate menu (Insert) turns it on and off.

Or install it by hand: download the .zip and drop it on the launcher window, or unzip it into its own folder in Mods\ beside Skate.exe.

Maps show up in the ReSkate menu's level list. To join a server running a custom map, you need the same map installed. If the game won't load after installing, see known issues.

skatemods doesn't host or review this mod. The download comes straight from Thunderstore. Only install mods you trust, because scripts can run code.