Path of Unarguable Wizardry

Based on the original subclass, Path of the Muscle Wizard, created by Middle Finger of Vecna, edited to have more official wording with a small rebalancing.

You're a wizard! Perhaps you went to wizarding school on a football scholarship or just picked up a book at the gym and started reading. No matter how you got here, you're a wizard, one that just coincidentally has massive, rippling muscles. You have the big dumb hat and the book filled with gibberish and everything!

You gently remind others, often by beating them to a pulp and cracking their bones, that your magical powers shouldn't be questioned. You're a good wizard, the best one, even! And only a fool would say otherwise.

Unarguable Wizardry

Starting at 3rd level, your unquestionable legitimacy (and immense pectoral muscles) gives you advantage on Charisma (Intimidation) checks made to convince others that you are, in fact, a wizard.

Additionally, if someone questions your legitimate magical prowess, you can instantly (no action) fly into a rage for 1 round. This rage ends at the beginning of your next turn (ignoring the Persistent Rage feature) but does not count against your total number of Rages per long rest.

"Cantrips"

At 3rd level, you can call upon your "magic" to cast "cantrips" in combat. You can use the following "cantrips" a number of times equal to your Strength modifier. You regain all expended uses when you take a short or long rest. While you are raging, casting your "cantrips" does not count against your total number of uses.

Mage Hand.  As a powerful mage, if you take the Attack action on your turn, you can use a bonus action to try to shove a creature within 5 feet of you with your hand.

Shocking Grasp. You hit your target even harder than usual, a fact which they find quite shocking. As a bonus action, the next foe you hit can't take reactions until the start of its next turn.

True Strike. You can prepare yourself to really, truly strike your target. As a bonus action, you designate one creature you can see within 60 feet of you as the target of this feature. The first time you hit that target with an attack, it takes an extra 1d8 damage from the attack.

When you enter a your rage, you may use one of your "cantrips" as part of the same action.

"Spells"

By 6th level, your "magic" is powerful enough to cast every "spell" that exists (and no one can or will prove otherwise without broken ribs.) However, you only prepare the following "spells" each day.

You can cast each of these "spells" once and recover all expended uses when you finish a short or long rest.

Burning Hands: Your backhand slap is legendary.  When you take the Attack action on your turn, you can use your bonus action to make an unarmed attack roll against each creature within your reach. On a hit, this strike deals 1d8 + your Strength modifier bludgeoning damage. This attack is considered magical for the purposes of overcoming damage resistance and immunity to nonmagical attacks.

Magic Missile: When you take the Attack action on your turn, you can use your bonus action to make a ranged weapon attack using a weapon on your person. If the weapon has the Thrown property, you may draw it as part of the attack. Because magic missile never misses, you have advantage on this attack roll.

Shield: As a reaction when you're targeted by an attack, you can quickly don a shield to defend yourself. Until the start of your next turn, you gain the shield's bonus to AC, including against the triggering attack. If you are hit by the triggering attack, you can reduce the amount of damage taken by 1d12 + your Constitution modifier. At the start of your next turn, you may choose to keep the shield equipped or put it away without expending an action or your interaction for the turn.

"Magical" Mastery

By 10th level, you're such an amazing wizard that other wizards can't even touch you. While you're raging, you have resistance to damage from spells.

Additionally, because of your absolute conviction of being a mystical wizard, any attack you make while raging counts as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

"I cast Fist!"

Starting at 14th level, you can crush your enemies with your ultimate "spell", Fist. While you're raging, you can use your action to punch your foe really, really hard. Make a melee attack roll, with advantage, against one creature within your reach. On a hit, you deal bludgeoning damage equal to 8d8 + your Strength modifier. This attack is treated as magical for the purpose of overcoming resistance and immunity to nonmagical attacks and damage.

Once you use this feature, you cannot use it again until your current rage ends and you spend at least one round not enraged.