Being a typical Chinese Novel protagonist and having 6000 chapters of lore behind him, Yang Kai has several incarnations, transformations, levels, skills, artefacts etc. which give him a variety of forms he can be used in a battle.
Think about a character you like and see how he fares against him.
Yang Kai scalings to use for your characters as reference points:
BOS Yang Kai (Sealed Dimension and first planet, scaling up to Island/Country level)
Starting Universe ("Starfield" Up to Large Star level)
Sealed Multiverse ("Star Boundary" Up to Multiversal+)
I know the Four Beast - he is in the country range but without any noticeable hax, right? From the ones mentioned, he should not push him far then, given at this point in time, YK had already developed some basic durability ignoring ability like spatial cutting.
BoG Dark Urge (Basic Level 1 adventurer. No Slayer Form, no Illithid powers, no memories. Just a dangerous instinct to kill. Wall level.): Gets one-shot by even BOS Yang Kai.
Mid-game Dark Urge (Has defeated Auntie Ethel (hag), Nere (True Soul), Phase Spider Matriarch, Grym (adamantine golem), Githyanki patrols, and a Beholder. May have unlocked early Illithid powers and involuntary Slayer Form. City Block to City level): Could challenge Tier 1 Yang Kai, depending on gear, hax and Slayer access.
End-game Good Path No Slayer, No Illithid (Breaks Bhaal’s curse, retains divine heritage but loses Slayer Form. Still defeats the Chosen of the Dead Three (Ketheric, Orin, Gortash), and Raphael (Archdevil’s son). Planet level): Solid match for Tier 2 Yang Kai.
End-game Evil/Neutral Path with Slayer Form (Embraces Bhaal’s power. Has access to full Slayer Form (divine avatar), defeats Orin even when she uses Slayer, and can overpower other god-chosen beings. Planet to Star level): Contends with or beats Tier 2 Yang Kai.
End-game Full Illithid Dark Urge (Becomes a Mind Flayer while retaining divine Bhaalspawn essence and controls the Netherbrain (a being feared by gods). Gains Crown of Karsus and psionic hax on a mass scale. Multiversal): Fits in Tier 3 with Sealed Multiverse Yang Kai.
Dark Urge with Mastered Crown of Karsus + Full Control of the Weave (Narrative high-end. Hypothetical version who fully understands the Crown and can manipulate the Weave like Karsus did (which disrupted magic across planes and killed a goddess). Multiversal to possibly Megaversal): Could fight or match Tier 4 Yang Kai, depending on interpretation of Far Realm and Weave cosmology.
BoG Dark Urge (Basic Level 1 adventurer. No Slayer Form, no Illithid powers, no memories. Just a dangerous instinct to kill. Wall level.): Gets one-shot by even BOS Yang Kai.
Mid-game Dark Urge (Has defeated Auntie Ethel (hag), Nere (True Soul), Phase Spider Matriarch, Grym (adamantine golem), Githyanki patrols, and a Beholder. May have unlocked early Illithid powers and involuntary Slayer Form. City Block to City level): Could challenge Tier 1 Yang Kai, depending on gear, hax and Slayer access.
End-game Good Path No Slayer, No Illithid (Breaks Bhaal’s curse, retains divine heritage but loses Slayer Form. Still defeats the Chosen of the Dead Three (Ketheric, Orin, Gortash), and Raphael (Archdevil’s son). Planet level): Solid match for Tier 2 Yang Kai.
End-game Evil/Neutral Path with Slayer Form (Embraces Bhaal’s power. Has access to full Slayer Form (divine avatar), defeats Orin even when she uses Slayer, and can overpower other god-chosen beings. Planet to Star level): Contends with or beats Tier 2 Yang Kai.
End-game Full Illithid Dark Urge (Becomes a Mind Flayer while retaining divine Bhaalspawn essence and controls the Netherbrain (a being feared by gods). Gains Crown of Karsus and psionic hax on a mass scale. Multiversal): Fits in Tier 3 with Sealed Multiverse Yang Kai.
Dark Urge with Mastered Crown of Karsus + Full Control of the Weave (Narrative high-end. Hypothetical version who fully understands the Crown and can manipulate the Weave like Karsus did (which disrupted magic across planes and killed a goddess). Multiversal to possibly Megaversal): Could fight or match Tier 4 Yang Kai, depending on interpretation of Far Realm and Weave cosmology.
Yeah. The main characters in BG3 are very impressive party for a bunch of people who are level 12. Usually, in D&D, adventurers at level 12 are around city level or island level. Depends on how impressive their accomplishments and feats are.