Parthunum can spend a bonus action to regain 1d10 + 20 hit points.

Parthunum can make a bonus action attack with the opposite end of a glaive, halberd, quarterstaff, or spear after attacking with that weapon.

Parthunum can make a bonus action melee attack after scoring a critical hit or reducing a creature to 0 hit points.

Parthunum gains the Polearm Master feat. When he takes the Attack action with a glaive, halberd, quarterstaff, or spear, he can use a bonus action to make a melee attack with the opposite end. Creatures provoke an opportunity attack when they enter his reach.

Parthunum gains the Great Weapon Master feat. On his turn, before making an attack with a heavy weapon, he can take a -5 penalty to the attack roll to gain +10 damage on a hit. A critical hit or reducing a creature to 0 hit points grants one additional melee weapon attack as a bonus action.

When a creature enters his reach while he wields a glaive, halberd, quarterstaff, or spear, Parthunum can make an opportunity attack.

Parthunum makes four weapon attacks when he takes the Attack action. He can use Action Surge once per short or long rest to take an additional action.

Parthunum may accept a -5 penalty to a heavy weapon attack roll for +10 damage on a hit.

Parthunum adopts the Defense fighting style. While wearing armor, he gains a +1 bonus to AC.

Once per short or long rest, Parthunum can take one additional action on his turn.

Parthunum chooses the Champion martial archetype.

Parthunum scores a critical hit on a weapon attack roll of 19 or 20.

Parthunum gains an Ability Score Improvement at fighter levels 4, 6, 8, 12, 14, 16, and 19. His choices are Strength +2 at level 4, Strength +2 at level 6, Polearm Master at level 8, Great Weapon Master at level 12, Constitution +2 at level 14, Alert at level 16, and Constitution +2 at level 19.

Parthunum can attack twice, instead of once, whenever he takes the Attack action on his turn.

Parthunum gains another Ability Score Improvement, increasing Strength by 2 to 20.

Parthunum can add half his proficiency bonus, rounded up, to any Strength, Dexterity, or Constitution check that does not already include his proficiency bonus. He also gains proficiency in Strength (Athletics).

Parthunum can reroll a failed saving throw. He must use the new roll and cannot use this feature again until he finishes a long rest.

Parthunum gains a second use of Indomitable between long rests.

Parthunum gains another Ability Score Improvement, increasing Constitution by 2 to 16.

Parthunum scores a critical hit on a weapon attack roll of 18, 19, or 20.

Parthunum gains the Alert feat. He gains +5 to initiative, cannot be surprised while conscious, and unseen attackers do not gain advantage against him merely for being unseen.

Parthunum gains a third use of Indomitable between long rests.

Parthunum regains 5 + his Constitution modifier hit points at the start of each of his turns if he has no more than half his hit points remaining and is not incapacitated.

Parthunum gains another Ability Score Improvement, increasing Constitution by 2 to 18.

Parthunum can attack four times whenever he takes the Attack action on his turn.

Parthunum has an excellent memory for maps and geography, and can find food and fresh water for himself and up to five other people each day, provided the land offers natural resources.