Swordmaster

You have spent many years training with swords and know them as weapons of offense and defense. Beyond weapons of brutal strength you understand the sword as a versatile weapon of war. You know the strengths and abilities of all sword types and how to maximize their use in battle. You gain unique abilities based on the type of sword you are wielding, but with any sword you can add half your proficiency in that sword to your AC as a reaction when attacked if you are proficient in that type of sword. 

Proficiency in a specific sword also grants the follow special skills:

Shortsword: Sword and Board, You may use a shortsword with a shield in your offhand and gain a shield bash as a bonus attack. The shield bash has a damage of 1d4 and your strength as a bonus to hit. If the shield bash hits the follow up shortsword attack has advantage to hit. 

Longsword: Versatile, You may use the fully versatility of this weapon and can transition a failed attack with the blade into a fast follow up attack bludgeoning murderstroke that does 1d6 damage and a chance to stun or can make an attempt to disarm your opponent. The target makes a strength or dexterity save based on which ability the attacker wants to use. The DC is determined by the attackers roll to hit plus their ability modifier plus proficiency bonus.

Greatsword: Reach, You know how to fully use the full reach of a greatsword and all greatswords have the reach modifier. You also have advantage against attackers using polearms. You may halfsword your greatsword and loose the reach modifier but gain +2 to hit. 

Rapier: Riposte, you may use a reaction on a missed melee attack against you to make a return attack. 

Scimitar: Curved blade, you can fully utilize the fast nature and curved edge of your scimitar to get past your opponent and unleash a flurry of blows. You can reroll any missed attack once.