Base Class: Barbarian
Honestly, there's so many takes on this subclass or exactly what it entails, so here's my shot at it. The several titles were because I really couldn't decide on one. Mainly inspired by Alexander Louis Armstrong from Full Metal Alchemist, Izuku Midoriya from My Hero Academia, and Gorgug Thistlespring from Fantasy High. It's mainly focused on expending uses of Rage to do cool arcane things.
Fresh Start
At 3rd level, you may expend a use of Rage to cast Magic Missile or Shield at the first level. When you reach 20th level, you have a set limit of 6 uses, one for each bone in your dominant hand. These may be cast while raging. You also gain the ability to cast Prestidigitation.
Learning Curve
At 6th level, when you reduce a target to zero hit points that has a flying, swimming, climbing, or burrowing speed while raging, you may lock it's patterns into your memory. The next time you use Rage, you gain that creature's movement speed, in distance and type.
Signature Spell
Once you reach 10th level, you may choose a spell from the Wizard spell list of 3rd level that doesn't require concentration, and that becomes your signature spell, which you've memorized from top-to-bottom. You may spend 3 uses of Rage to cast it. When you reach 20th level, you can cast the spell at will, but take 3d12 force damage whenever you do. If the spell forces a target to make a saving throw, the DC is 11 + your Constitution modifier.
Greatest Wizard of All Time
At 14th level, you have gained a reputation, heroic or villainous, that precedes you, so that in the moments when you strike true- you strike, alright.
When you score a Brutal Critical against a target while raging, you may deal maximum damage, ignore all resistances and vulnerabilities, and push the target a number of feet equal to your Barbarian level. After you fall out of raging, you gain a level of exhaustion.