DxD world info

Tier 10: 0

Regular humans, animals, and other creatures with absolutely no magical power.

Tier 9: 1-99

Anyone from the weakest magic user (including but not limited to Issei when he was initially revived) to just below the average low-class devil. Can also apply to sorcerers who've just started their training.

Tier 8: 100-199

The varying power degrees of a normal low-class sorcerer, devil, angel, fallen angel, etc. Also applies to most magical creatures. Examples: Raynare (pre-revival), Kiba Yuuto (Vol. I-II), Koneko Toujou (Vol. I-III), Asia Argento (Vol. I-III), Genshirou Saji (Vol. I-III).

Tier 7: 200-299

The stage between low and middle class.

Tier 6: 300-399

Beings with middle-class magical power. Examples: Issei Hyoudou (Vol. VI), Kiba Yuuto (Vol. III-VI), Xenovia Quarta (Vol. III-VI), Irina Shidou (Vol. III-VII).

Tier 5; 400-499

The stage between middle and high class. Examples: Akeno Himejima

Tier 4: 500-999

High-class power. Examples: Rias Gremory (Vol. I-VIII), Sona Sitri (Vol. I-V)

Tier 3: 1,000-9,999

The stage between high and ultimate class. Examples: Michael Eon (Vol. I-VI), Kuroka (Vol. II-?), Sairaorg Bael (Vol. V-VII), Issei Hyoudou (Triaina forms).

Tier 2: 10,000-99,999

Ultimate-class. Examples: Zach Praktum (Vol. I-?), post-revival Raynare (Vol. III-?), Michael Eon (Vol. VII-?), Sairaorg Bael (Vol. VIII-?), Issei Hyoudou (Cardinal Crimson Promotion).

Tier 1: 100,000-999,999

Satan/Seraph/Gov. General-like power. Examples: Serafall Leviathan, Azazel, Shimezhai, Michael the Archangel, Gabriel, Metatron.

Tier α: 1,000,000-9,999,999

Gods, Super Devils, certain monstrous gods, various Lovecraftian creations that might make appearances in the story much later on, and the Heavenly Dragons. Examples: The Demiurge (AKA God of the Bible, AKA Yahweh, AKA Yaldabaoth), Rizevim Livan Lucifer, Sirzechs Lucifer, Ajuka Beelzebub, the Leviathan God, Ddraig, Albion.

Tier Ω: 10,000,000-∞ minus 1

The amount of power reserved for those who are above the normal gods and can bring about the end of the timeline. Known Examples: Ophis, Great Red, Trihexa, Gaia, Tartarus, Ouranos.

This is the power level scale that I'm going to use in the DxD world

I'm going to put Sephiroth at high class devil or tier 4 power level in the beginning because his body was just remade and while he was extremely powerful in his old world in this one their are Gods in this one where in his old world there wasn't plus he doesn't have his sword taking away one of his superior abilities. While he has complete control of almost all elements of magic there are some forms of magic that are to unique like Rias. Then there is Senjutsu, Yojutsu, Touki there isn't really anything like it in his old world that I know of so something different as well.