MC Info Dump (Slight Spoilers / Read at own risk)
Background -
Regular guy dies and gets reborn into the Marvel MCU AU (AU since it will include mutants and some comic bits, plus some parts I had to create from scratch, just consider it a sister reality of the MCU). Guy gets reborn as the son of Hela and unknown father, he is born akin to Sweet P from adventure time- while not immediately larger he will be BEEG. He is born long before Thor or Loki and for all intents and purposes appears to have the same affinities as his mother- war and death. MC hasn't seen adventure time, he doesn't initially know about the Lich and even when he does he won't think it to be a primordial force of death.
Powers -
Base: Mc is gonna basically be Sweet P from Adventure Time (Not as much in looks or attitude, but more his powerset), this makes him have the basic abilities from Sweet P such as increased strength, durability and size (MCs size will be attributed to his giant heritage).
Lich: Lich aspects will come into play down the line with powers such as necromancy, necrotic/corruption flames, disease/mutagen/death/blight affinity, Eldritch knowledge, Possession, Telepathy, Empathy, soul manipulation and death breath (ye idk what else to call an ability to basically turn people to dust by breathing at them.)
Mutation: Won't spoil but MC will get a mutant ability and yes this does mean his father is human.
Domains: He has gained a single domain courtesy of being Asgardian and being born with latent God-force (It'll be revealed near the beginning), the other 3 domains are gained from the Lich, one being death (exceeding his mother) and the other 2 being a secret as well.
MC's Looks -
MC age 0 - 1: MC will be born at the size of a larger than average baby with blue eyes, 2 stubby curling horns, black hair, pale skin and will grow very quickly- being the size of a 3 year old when he turns 1. Growing up he will be big but not tubby (Big in terms of physique, even if he were scaled to someone of his size, he would still be a big boi).
MC age 3: MC wields a single sword and wears armor similar to a roman centurion minus the frill on the helmet. He has grown up in war and made his first kill, he is now the size of a 10 year old.
MC age 5: Being the son of Hela he now wields 2 regular swords which rest on each hip (His maturity, strength and parentage make it so he constantly trains with different melee weapons). He is strong enough to wear plate armor without hindering his speed and makes the most of it. He is now the size of a 15 year old (Imagine a 5 year old scaled up similar to how primarchs from 40k are scaled up and not mega lanky).
MC age 10: MC is now the size of a tall adult and has switched his swords for a large mace, he wears extremely thick and spiky plate armor (not just to protect him but to make him a pain train when he runs into his enemies). He has started touching on his domain- helped heavily by following his mother into several battlefields.
MC age 20: MC is now the size of an upright bus but can shrink himself to normal proportions through magic. He now wields a mace created by his mother through which he can channel green flames and gravity manipulation- for wide area and single target attacks respectively. His weapon and his plate armor are both made from Uru metal and will be his main gear for a while, they can shrink or expand just like he can but both weigh A LOT. The mace looks exactly like Saurons but with green flames at the tip, the armor looks like the kryptonian armor from man of steel minus the helmet, the helmet itself looks like the warriors from Final fantasy 14 but instead of metal horns his actual ones will instead be in their place. He has short black hair and is reasonably attractive- not Adonis but certainly not ugly by any stretch (especially when you consider his parents).
MC age 1000: MC's true size equals that of godzilla (120m give or take).
MC age 5000: MC's true size caps out at the size of a mountain (500m give or take).