Iron Vanguard

The Iron Vanguard fighter favors heavy armor, a weapon in one hand, a shield in the other, and a volley of creatures that they seem to shrug off.  Sure, it may not be flashy.  Sure it might seem suicidal to simply charge in without a care.  But the Iron Vanguard has the hit points and armor to withstand even the most brutal blows, and come back for more.  Let the wizard play tactical, you simply laugh as enemies bounce off your shield.

The Iron Vanguard relies heavily on typical sword and board combat, favoring resisting damage while at other times regaining more health through an almost unnatural vitality, making them very hard to bring down if something actually manages to get past their defenses.

Tide of Iron

Requires a Shield.  At third level, moving 15 feet or more allows you to make a Shield Rush attack as a bonus action.  On a hit, you deal 1d4+strength modifier damage, and the target must make a strength saving throw or be pushed back 5 feet and knocked prone.  If this attack would cause the creature to collide with another creature, both take 1d4+strength modifier damage, and are knocked prone.

You may use this a number of times equal to your Proficiency bonus, and regain all uses after a short rest.

Stand Your Ground

At level 7, you have a reduction to non-magical damage equal to your Constitution modifier.   In addition, when subjected to an effect that would cause you to be moved or knocked prone, you gain advantage on any rolls to resist the effect or stay on your feet.

Unending Vitality

At level 10,  you gain an additional use of Second Wind.  In addition, a roll of 5 or lower on Second Wind hit die is considered to be a 6 instead.

Outnumbered, Not Outmatched

At level 15, you gain a +1 to AC for every hostile creature adjacent to you.  In addition, your Tide of Iron feature no longer requires you to move to trigger the effect, and can be used as an Attack Action or a Bonus Action.

Unbreakable

At level 18, when you are subjected to an effect that would require a Dexterity saving throw, you may instead choose to use your Constitution Save instead.  In addition, the damage resistance from Stand Your Ground is doubled, and now includes magical damage.

In addition, you gain a third use of Second Wind.