Charon, The Ferryman.

4 Armed Brawler. The Ferryman has 4 arms at his disposal, allowing him grapple and attack all at once. 

When the Ferryman makes an attack, he can choose to grapple the opponent. If succesful, the opponent is restrained and the Ferryman makes any attacks with advantage on that opponent as long as they are grappled. Additionally, he can decide to throw a grappled opponent by rolling a Strength Check. (See Throw Action.)

If he attempts to hit another character, he has to make a ranged attack throw. 

Issin Skin. The Ferryman has resistance to spell attacks made against him. This effect only applies on spells that inflict physical harm upon him.

Brutality. Upon landing a critical hit, the opponent has to make a CON Save (17) or be rendered unconcious for 1 round. A teammate can wake them up with a succesful medicine check. (17)

Multiattack. The Ferryman makes 4 attacks. Punches count as 1 attack. Throws and swings count as 2. Impale counts as 3.

Punch. Melee Weapon Attack: +10 to hit, reach 10 ft., single target. Hit:  16 (4d6 + 7) bludgeoning damage. Upon a succesful hit, The Ferryman can attempt to make a grapple. If not, he can decide to shove them away 20ft instead unless they make a STR Save (17). If they hit a wall, they take 1d10 bludgeoning damage and are knocked prone. 

Throw. Ranged Weapon Attack: +8 to hit, range 60ft, single target. Hit: (4d8 + 12) bludgeoning damage. When hit, the target must make a STR Save (17) or be knocked prone. 

Swing. Melee Weapon Attack: +10 to hit, Reach 15ft cone, multiple targets, Hit: 23 (5d8 + 7) bludgeoning damage. This attack can only be done when an opponent is grappled. 

 Impale. Melee Weapon Attack: +12 to hit, range 15ft, single target. Hit: 40 (5d12 + 20) piercing damage. Upon hit, the enemy must make a Dex Save (18) or be considered grappled and crippled. Crippled enemies have their movement speed halved, disadvantage on all saves and attacks

"Come here, you." - The Ferryman picks up an object which he can use to increase the strength of his punches with an additional +5, or which he can decide to throw. The object will break upon impact. 

Merry-Go-Round - If the Ferryman is holding an opponent, he can use his bonus action to spin them rapidly in some creative way. They must make a CON Save (17) or be Stunned until the start of their next turn.

Down for the Count - If the Ferryman is adjacent to a prone opponent, he can use his bonus action to pin them down to the ground. The opponent must make a contested STR Check with disadvantage or be Restrained until The Ferryman moved from his position, or they make the STR Check on their next turn. They must use an action to do so. 

"My Turn" - When a melee attack is made against the Ferryman, he can use his reaction to attempt to grapple their attacker with advantage. 

The Ferryman has 3 Legendary Actions Total. 

Detect (Costs 1 Actions). The Ferryman makes a perception check.

Leap (Costs 2 Actions). The Ferryman jumps 40ft in any direction, though he can only go up half as far. (20ft)

Iron Grasp (Costs 1 Action). The Ferryman launches his metal fist towards his opponent in an attempt to grab them and drag them within range. This Legendary Action counts as a ranged attack. (+8) This move deal 4d6+7 bludgeoning damage. The enemy makes a DC17 Strength Save or is dragged towards the Ferryman and considered grappled.

Mercy Kill (Costs 3 Actions, 1 time use.) The Ferryman uses his Iron Grasp Legendary Action, but follows it up with an Impale.

Legendary Resistance. (Costs 1 Action/Restricted to twice per round.) If the Ferryman fails a save, he can decide to succeed instead.