SAO fighter

they can use different kinds of strikes. their swards start to glow a different color based on how many strikes you do. 

1 strike: orange: on the a hit you guaranty a critical hit 

2 strikes: red: all strikes have advantage

3 strikes: blue. deals and extra damage die 

4 strikes: purple: gives you disadvantage but every strike is a critical hit. 

orange strike

Beginning when you choose this archetype at 3rd level, your weapon attacks score a critical hit when you use orange or single strike. twice per long rest 

you can only do this once per round until level 18.

red strike

Starting at 7th level, you can add half your proficiency bonus (round up) to any Strength, Dexterity, or Constitution check you make that doesn’t already use your proficiency bonus.

you gain the red strike or two strike attack all your attacks this turn has advantage 

you can only do this once per round until level 18.

 3 times per long rest 

blue strike

you make tree attacks and all give an extra damage die

you can only do this once per round until level 18.

twice per short rest

purple strike

you make four strikes at disadvantage but all are critical hits

you can only do this once per round until level 18.

twice per short rest

master

you can use more than one strike in one turn.