Solo Leveling System with Upgrade

Levels of Power (Level)

Student

1-10

Genin

11-20

Chunnin

21-30

Special Jounin

31-40

Jounin

41-60

Kage

60-80

Madara / Hashirama

90-100

Hagoromo

101-200

Kaguya

200-300

Levels of Power (Status)

Student

Strength: 1-10

Vitality: 1-10

Agility: 1-10

Intelligence: 1-10

Directions: 1-10

Genin

Strength: 11-20

Vitality: 11-20

Agility: 11-20

Intelligence: 11-20

Directions: 11-20

Chunnin

Strength: 21-30

Vitality: 21-30

Agility: 21-30

Intelligence: 21-30

Directions: 21-30

Special Jounin

Strength: 31-40

Vitality: 31-40

Agility: 31-40

Intelligence: 31-40

Senses: 31-40

Jounin

Strength: 41-60

Vitality: 41-60

Agility: 41-60

Intelligence: 41-60

Directions: 41-60

Kage

Strength: 60-80

Vitality: 60-80

Agility: 60-80

Intelligence: 60-80

Senses: 60-80

Madara / Hashirama

Power: 90-100

Vitality: 90-100

Agility: 90-100

Intelligence: 90-100

Directions: 90-100

Hagoromo

Power: 101-200

Vitality: 101-200

Agility: 101-200

Intelligence: 101-200

Directions: 101-200

Kaguya

Power: 200-300

Vitality: 200-300

Agility: 200-300

Intelligence: 200-300

Senses: 200-300

Obs: 1 Vitality = 50 Hp

Obs2: 1 Intelligence = 50 Mp

Obs3: This only affects those who have contact with the system, that is if a Nara is invited to the group he will have a huge amount of Mp, and once this occurs the chakra of that person will increase permanently

Now that you have an idea of the level of power imagine how Sora will be able to face Kaguya. And he'll have to do it if he wants it on the harem.