Aleth Skinfuser, Ultimate Flesh Fusion

Technology Fusion. Aleth can attune to 6 magical items and gains +1 to each saving throw he makes for each magical item he's attuned to. Additionally, if he is reduced to 0 hp, he can choose to end his attunement to one of his magical items, and instead be dropped to 1hp. Lastly, magic items Aleth carries do not give off magical auras and while attuned to an item it can not be seen by other creatures.

Technology Possession. Aleth is attuned to a Helm of Awareness (Can't be surprised and has advantage on Initiative Rolls), Arcane Propulsion Armor, Necklace of Adaptation (Adv against saving throws made against harmful gases and vapors, and can breath normally in any environment), Gloves of Missile Snaring, Cloak of Protection (+1 to AC and all Saving Throws), and Belt of Hill Giant Strength (21 Strength).

Flesh Connectedness. Aleth is connected to a 110x110 area of flesh bellow him. That space counts as Aleth for all intents and purposes. Any damage it takes Aleth takes. 

Multiattack. Aleth uses his Bones ability if he has it, then makes a Flesh Fist attack and either an Unsettle Flesh attack or uses Overhaul.

Bones (Recharge 5-6). Aleth targets one creature. That creature must make a DC 22 Dexterity Saving Throw or be hit by a pillar of bones. The target takes 3d10 Piercing Damage and is pushed up to 60ft in any direction. If they hit a ceiling or wall, they take an additional 1d6 damage for every 10ft moved and are restrained until they make a DC 22 Strength Saving Throw (Which they can attempt as an action).

Extended Fist (Recharge 6). Aleth summons a fist of flesh as if he'd casted Bigby's Hand.

Flesh Fist. Melee or Ranged (20/60) Weapon Attack: +11 to hit., 1 target. Hit: 11 (2d8 + 5) bludgeoning damage plus 10 (2d10) necrotic damage.

Unsettle Flesh. Melee  Weapon Attack: +11 To hit, 1 target. Hit 15 (3d8) necrotic damage and the target must make a DC 22 Constitution Saving throw or have disadvantage on Saving Throws, Ability Checks, and Attack Rolls for one minute. A creature effected by this can remake the save at the end of their turns. This counts as a Poison Effect.

Overhaul. Aleth targets a creature he can touch within 5ft of him, the target makes a DC 22 Constitution save. If the target is affected by Unsettle Flesh and has lower than 50 hit points, the target is killed and Three-Quarters of their body explodes. If Aleth targets himself, he automatically explodes regardless of his HP or being affected by Unsettle Flesh 

Flash of Genius (5/Long Rest). Aleth can add +5 to an ability check, saving throw, or attack roll, that he or a creature within 30ft him makes.

Aleth can use 5 Legendary Actions per round. If he takes more than 40 damage from a single source he looses one legendary action.

Deconstruct and Reconstruct (Costs 2 Action). Aleth uses Overhaul on himself. He then reappears in a space up to 60ft away as if he'd not used Overhaul.

Flesh Sweep (Costs 3 Actions). Aleth choose 10 10x10 connected squares within his area. Creatures in that area must make a DC 22 Dex Save or take 4d10 Bludgeoning damage and be pushed to anywhere within the area chosen.

Flesh Fuse Gauntlet  (Costs 2 Actions). Aleth uses either Unsettle Flesh or Explode Body.

Shift. (Costs 1 Action). Aleth moves his movement without provoking attacks of opportunity 

Villain Actions. On each round at the end of another creature's turn Aleth can take a villain action.
 Round 1, "I WILL HAVE YOUR BODIES" - Aleth can move without provoking Attacks of Opportunity and make one melee attack.
 Round 2, "MY NEW BODY IS SUPERIOR" - Aleth heala 20 Hp and regenerates any lost limbs. He then makes one melee attack.
 Round 3, "I WILL ABSORB YOU!!!" - Aleth make 2 Flesh Fist attacks against each creature in his space. If both attacks hit the target is restrained and takes 2d8 necrotic damage at the start of each of their restrained turns. A restrained target can make an Athletics check as an action to escape, acting as a grapple.