You are a gladiator :)

Arena fighting training

At level 3, you lose profiency with heavy armor and gain proficiency in performance(CHA). Also, you now have access to powerful fighting styles made possible by your unorthodox training. Whenever you choose a fighting style to master, you may choose one of these instead. :

Retiarius: Nets gain the light property as long as you wield them and may be used in your off-hand without problem. Whenever you succeed in restraining an enemy with a net, you can immediately attack the restrained target with any weapon already equipped.

Murmillo: You may use your strength modifier instead of your dexterity modifier when using light or medium armor.

Provocator: Once per turn, when you roll damage for an attack, you may half the damage done to the enemy and attempt to goad the target into attacking you. Make an intimidation check (STR or CHA) against the target's wisdom ability. If you are sucessful, the target must attack you on its next turn, if it is possible within its movement range. The target may pursue you without provoking attacks of opportunity from prior engagements.

Thraex: Once per turn, if you are wielding a shield, you may use the active defense action. 

Active Defense: Until the start of your next turn, whenever an enemy targets you with a melee attack, make a dexterity saving throw against the result of their attack roll. If you succeed, prevent all damage from this attack and you may take an opportunity attack with a melee weapon.

 

Decisive blow

Once per attack, when you roll for an attack, if you do not already have disadvantage, you may choose to give yourself disadvantage to gain a decisive die.

Before rolling for an attack you may choose to strike a decisive blow. If you do, roll all your decisive dice. Then, roll the attack and add the result of any amount of decisive dice rolled to the result of the attack roll. If the attack hits, add all the remaining decisive dices' results to the damage dealt. 

Lose all decisive dice when the combat ends.

Decisive Die:

lvl 3 = d6

lvl 10 = d8

lvl 15 = d10

Glorious executionner

Starting at level 7, when you drop a creature to 0 hit points, you may spend a decisive die and choose one of the following bonuses:

• Glorious finisher: Other friendly creatures than can see and hear you gain 1d6 + your performance modifier(CHA) + your proficiency bonus temporary hitpoints
• Gory finisher: Hostile creatures than can see and hear you make a wisdom saving throw (8 + your performance modifier(CHA) + your proficiency bonus). If they fail they have disadvantage on attacks made against you until your next turn. If a target that was goaded by you fails this saving throw, they are no longer goaded.
• Efficient finisher: Immediately make a melee attack on a hostile creature within range. This does not count towards your normal attack count.

Extraordinary resilience

Starting at level 10, you have advantage on deception checks to hide minor injuries and status effects. 

Also, on your turn, you may take an action to roll one of your decisive die and gain temporary hitpoints equal to the result. Whenever you do this, mark one point of exhaustion.

Artist of death

At level 15, you learn the following executions in addition to your existing ones:

• Reveling finisher: Refresh your use of Second wind.
• Enraged finisher: Until the beginning of your next turn, gain resistance to all physical damage, and you can't be charmed.

Additionnaly, you may now choose to use any number of decisive die to give in to your executing inspiration:

• Legendary finisher: Instead of using only one decisive die, use up to 5 decisive die. Then, for each decisive die used, choose one execution that hasn't been chosen yet, and add its effect to this finisher. Once you use this execution, you must finish a short or long rest before you can use it again

Apex of battle

Whenever you roll for initiative or use your action surge, gain an amount of decisive dice equal to your proficiency bonus, minus your exhaustion.

Additionnaly, whenever you kill a creature, you have advantage on all charisma checks on intelligent creatures that have witnessed it.