Unlearning shame by infodumping about my oldest and arguably cringest blorbo:
Way back in late middle & early high school, I took my basic knowledge of Magic the Gathering lore and created Ikeru Shikabane the Ronin Wraith, my planeswalker OC, a multiverse-wandering cyborg zombie samurai wizard.
He was first reborn on Mirrodin (living metal world) as a mindless but powerful undead slave of a necromancer, but regained his free will when the necromancer was killed, and the shock of that ignited his long-dormant planeswalker spark (special multiverse-traveling power). Desperate to avoid being re-killed by the warriors who killed the necromancer, he instinctively planeswalked away and found himself in Kamigawa (feudal-Japan-themed world).
There, he was taken in by a daimyo who gave him his name (which according to google translate is literally just "living corpse" in Japanese), taught him the ways of a samurai and encouraged him to hone his talent for magic. Ikeru was grateful, but never sure whether the daimyo saw him as just a weapon or as an adopted son. And before he could settle the matter, the daimyo was killed in war.
Having lost two masters in a row, he became a ronin, wandering first Kamigawa and then the multiverse, hiring out his services to those in need. On a visit to Mirrodin, he got curious about his past life, and found evidence that he wasn't native to that plane. This gave him a new purpose in his wandering, searching for any leads to who he was before dying. So far all he knows is that he was a planeswalker back then too, and that he had powerful enemies...
His speech and behavior is cold and blunt, but his actions show a kind heart, and he's a very "screw the rules, I'm doing what's right" kind of character with zombie ruthlessness tempered by samurai honor. To reflect this, he uses both black and white mana, and his magical specialty is working with ghosts, especially channeling them to gain their power. Not sure what a thematic deck for him would be like, but I figure relatively few creatures with a lot of spell support.
And if I were still following the game's plot I'm sure he'd have strong opinions about Mirrodin becoming the new Phyrexia (body horror cyborg world) and whatever they're doing with Kamigawa now (I hear it's cyberpunk?), but I haven't paid attention to Magic for years now ever since I realized the parts of it I like are subservient to the parts that bore me.
Anyway here's some Hero Forge minis, not exactly how I envision him but pretty close, and you can use the links to see them from other angles (you don't need an account or anything):
Fighting: https://www.heroforge.com/load_config%3D52045277/
At peace: https://www.heroforge.com/load_config%3D52050029/