The following is mentioned by Maruyama in the Author's Blog Chat covering the power level of the new world:
Translated: Clementine (Black Scripture Equipment) > Gazef (All 5 Kingdom Treasure Equipment) > Clementine (Equipment used during the fight against Momon) > Hamsuke > Gazef > Brain > Gagaran > Zero > Wall (Possibly meant as the max average human's possible limit thru hardwork, this is just a conjecture) > Zaryusu > Climb > a tiger > average human
Power level of Floor Guardians according to author: (strongest to weakest)
Shalltear Bloodfallen Mare Bello Fiore Albedo Cocytus Gargantua Demiurge Aura Bella Fiora Victim
Power level of Nazarick according to author:
1st - "8 Hierarchy" ("Nazarick's maximum strength") 2nd - Rubedo (Strongest NPC) 3rd - Touch Me (Strongest Warrior, World Champion) 4th - Ulbert Alain Odle (Strongest Magic Caster, World Disaster) 5th - Momonga (Fully-equipped) 6th - High Tier Floor Guardian (Shalltear and the likes) 7th - Sebas Tian (in Dragon form) 8th - Guren (7th floor Area Guardian) 9th - Low Tier Floor Guardian (Aura and the likes) 10th - Others (Pleiades, Hamsuke, Sharyusu, Zenberu, etc.)
New World's power rating / 3 = Yggdrasil level
Evileye evaluated Jaldabaoth difficulty power as 200 or more. (200 / 3) = 66.6
Lakyus evaluated Evileye as 150. (150 / 3) = 50
Lakyus evaluated herself as 90. (90 / 3) = 30
The Captain of Black Scripture is stronger than Solution.
Nigun exclaimed that a lone Dominion of Authority killed a Demon God 200 years ago.
Momon said that the Dark Knight of the Thirteen Heroes was possibly a Cursed Knight. It has a level requirement of 60 but from the stories, the Dark Knight should be at least level 70.
By using #15, #16, we could assume that the Demon Gods or Evil Deities have a wide spectrum of level, possibly 40-60.
Brita is an Iron-class adventurer.
Lizzie is stronger than Nfirea and Brita.
Sword of Darkness is a group of Silver-rank adventurers.
Foresight, Green Leaf and Heavy Masher are all equal to Mythril-ranked adventurers.
Kralgra, Sky Wolf and Rainbow are all known to be Mythril-ranked adventurers.