Just to rehash some of the tier 2 stuff so that some discussion and consensus happens on this. I will purposely leave ambiguity on HD-2D scaling to avoid spoilers and to avoid doing the spoiler marking
Feats
Gods and Goddesses
Every single god is responsible for the creation of at least 1 or more worlds (which should be assumed as universes with a space-time unless something contradicts), so let’s go through them
Rubiss - Created Torland and the Overworld
“The Goddess” - Created the “Real World”, Nadiria (I imagine Dark Prince has something, but I don’t remember the lore from it), likely the Dream World (taking the Zenithia statement from 5, although there’s also the fact that it was created from people’s dreams, so idk on this one), possibly the DQ8 world (Only going by name. Very possible the DQ8 world has its own creator goddess we don’t know of), possibly the Heroes Worlds (For the same reason as 8)
The Almighty - Created the DQ7 world (Maybe more but I need to beat 7 still)
Zenus - DQ9 world (Maybe more but need to beat 9)
Yggdragon - Created the DQ11 world (Maybe more but need to beat Treasures)
It’s unknown whether they created them all at once or not, but the feats should each be at least Low 2-C
Mortamor
Stated by a Zenithian Scholar that his ultimate goal was to absorb both the Dream World and the Real World + all other worlds. From absorbing and maintaining two space-times, this feat should easily be 2-C. There shouldn’t be doubt in this, considering he actively planned this, which should make the “all other worlds” part 2-B.
Rhapthorne
Rhapthorne’s plan was similar, except he planned to merge the Light World and Dark World. Iirc, there were some arguments on these being their own multiverses, but I’m pretty sure there was some loose evidence on these. Let me know on the overall consensus on this, but the feat should be 2-C.
Rhapthorne also is consistently stated to be able to contort the Space-Time Continuum with his magic, so this is consistent with the other feat and provides some scaling for at least a part of these feats.
Calasmos and Cohorts (Mordegon + Superbosses)
Calasmos is stated to be the greatest threat to Erdrea and wishes to “return all to the void.” I feel like it’s reasonable to assume he was planning on destroying Erdrea, which should put him at that level. Scaling with Yggdragon should also do that.
The End of Time, being Calasmos’ equal, is repeatedly stated to be able to damage space and time in different ways, even after his reveal as the Friend of Time. One Tockle after his defeat suggests they are the flow of time, which isn’t entirely out of the realm of possibility as a figurative statement, given they’ve overseen the flow of time across the worlds of different heroes and exist outside space and time. This suggests the Friend of Time could theoretically break space-time across several worlds. This is 2-C at bare minimum.
Mordegon in another world as the Timewyrm grew powerful enough off of Calasmos’ evil to destroy his own world, worded as “damned to darkness.”
There’s a lot of other feats, but their own feats stand from Low 2-C to 2-C
Velasco and Shadroth
Velasco operating entirely off of some dark magic could create a spell that would’ve destroyed the 4, 5, 6, and 8 worlds. Assuming this also includes adjacencies like Nadiria as Psaro is technically recruitable, this is at least 8 universes, (The Real World at 3 different times, Nadiria at least twice, the Dream World, and both Light and Dark World). I still need to look at the cutscene as of writing this, so this could theoretically include more world ls if he said “all worlds” at some point, which I vaguely remember.
Shadroth being a god of darkness and the source of Velasco’s power, should inherently be above this spell and scale the Heroes to it. Shadroth also fought the goddess in his world, which should put them around the same level.
Nokturnus
He destroys worlds on a whim, should easily be at least Low 2-C without scaling
Scaling
All of the final bosses and heroes (minus Calasmos and Nokturnus)
Via the Hall of Remembrances, every boss is fought together and have gained the power of their respective villain, which should make them and all end game heroes at roughly the same level.
This is also consistent with what-if post game and bonus scenarios like DQ9’s, DQ 10’s, DQ Heroes, and the oncoming DQ7’s.
HD-2D remakes have connections with 3, which scale the final enemies to around Zoma’s level.
This also applies to other villains and superbosses, as Estark scales to Eight, Zoma to the DQ Heroes’ heroes, and a certain final + post-game boss to the Scions.
The final bosses also usually have some equality or superiority to the creator goddess + the game constantly mentions light v dark, so they should all be equal to each other in terms of creative and destructive power, putting their power at the same levels as the bosses’ destructive power.
Calasmos, Nokturnus, and the original Luminaries (Eleven and Erdwin)
These characters standout from the rest in terms of scaling
The End of Time created the Hall of Remembrance bosses and is fought afterwards, which should be a pretty clear power difference.
Nokturnus slaughters Mortamor and uses the other final bosses as pawns in Battle Road Victory (Going off of that one scan)
The original luminaries obviously fought Calasmos and should scale slightly below him (due to having parties), and Mordegon as well due to having influences of Calasmos’ power and fighting a weaker party without the supreme sword or super sword.
These should put them solidly above the other heroes, but I feel it’s worth mentioning a few outliers, such as Nokturnus’ various appearances (given his superiority to Mortamor being impossible to scale the heroes to), and both his and Calasmos’ guest appearances (Primarily in the monsters series). Given they’re both in a league of their own compared to other final bosses, it doesn’t make sense to scale anyone else to them through side content.
Consensus
These could be debated, which is why I’m bringing them up, but there’s plenty of feats that keep the upper/god tiers in at least eight universes into 2-C, and likely countless into 2-B if Velasco’s or Mortamor’s feat/plans mean anything more.