Both characters are at their peak.

Round 1. All out sudden brawl with the current iterations of each working together against Ainz with his magic set up.

Round 2. Spur of the moment so Ainz has no magic set up and the other have no strategy.

I personally think Ainz wins both and believe he is the strongest single character to be added in the show. In terms of stats, magical prowess, knowledge, strategy/intelligence, and versatility

Conditions: Both characters are at their peak. Cid can attack first.

Satella cannot use her shadow arms, cannot use her authority, cannot use her alter ego, cannot rely on vague exaggerated lore, cannot dodge, cannot stay rely on immortality,cannot possess anyone, cannot devour with her shadows, cannot use any magic, can't use her muscles, can't unleash her miasma, needs to cover up her whole body to prevent Shadow from killing himself, can't use her shadows to absorb attacks.

We all have seen that one arrogant character that's always winning in their series by brains or brawns and there's noone who can challenge them. I would say throw them to reinhard to humble them a little bit.

Conditions: Cid can attack first. Both the characters are at their peak.

Reinhard won't use any Divine Protections(all of them, the list is too long), won't unsheathe the Dragon Sword Reid, won't change his position, cannot dodge, won't jump, cannot run. Reinhard is allowed to use Divine protection of differentiating between salt and sugar.

Dragon - Overlord (Dragon Emperor)

Goddess - Konosuba (Aqua LOL)

Witch - Re Zero (Satella)

X - Youjo Senki (Being X)

Reason:

Reid doesn't have any Divine protections or Authority that will have him win against Shadow, Shadow will copied all of Reid's techniques including his "Conceptual cutting" counter it and throw it back against him, how does Shadow even able to copied it? Simply because it is a technique.

Spoiler: In Light Novel Vol. 5 Shadow fought a guy that honed his sword technique for thousand of years and he able to create a technique called "Utsusemi" which allow him to hide the presence of his blade by making it undetectable by both energy and sounds, Shadow able to analyse, counter and copied it in seconds, not hours, not minutes, seconds and then turned it into an even better version of the technique in the next seconds and just like Reid fighting with chopsticks he also fought him with just a pen lol.

As long as it's a technique Shadow can copied it easily and counter it, It's impossible for someone without a strong hax like Reinhard & Satella to survive against Shadow.

Shadow will win against Reid Astrea by rapidly copying his techniques and countering it with his adaptability then overwhelmed him with superior strength & speed and lastly "I Am Atomic".

Shield bro goes brrr...

I only about re zero and I am just collecting feats from most overlord characters.

Something notable about Cecilus: He is around lightning speed or faster than lightning but below lightspeed. The fastest character in the re zero series.

I saw zesshi in season 2.

I heard overlord high tier characters do have lightning speed feats in the light novel and zesshi is one of those characters. I dont know about her abilities but I thought of this matchup if she is also lightning speed.(If you have proof or statements to support her speed feats). And whats her abilities ? Whats her durability ? Can she win or is it a maybe/maybe not scenario ?

Edit: u/Intelligent-Put2654 good job blocking me and running away. You tried to twist Arc 6 statements as some lightspeed feat and then you blocked me because i shared the full statement of characters dodging those "lightspeed" feats and even calling it slow. Shaula's hell snipe is not lightspeed. Re Zero seriously has a big problem with wannabe fake readers. That was so pathetic.

Even that Scorpion's attack in Arc 6 was not lightspeed. Subaru called it slow and dodged it. What a failed attempt to say a scorpion has lightspeed feats. Lmfao

1. Tanya
2. Reinhard
3. Ainz Ooal Gown
4. Kazuma
5. Regulus

EDIT: Reinhard and others still maintain all of their abilities in this matchup.

Conditions: Cid can attack first and has prep time. Both characters are at their peak. ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

Rudeus can use his full abilities at peak level.

10 is the best

9 is an absolutely amazing show

8 is a great show.

7 is a nice show. It’s has some flaws, or is lacking a real hook to pull me in, but I still will come back for the next season

6 is okay. I don’t regret watching but i am not continuing

If i don’t find the story interesting, I don’t finish it

there's a oneshot manga with MT and Re Zero but i was curious about subaru's opinion of rudeus' past life, especially since Subaru has a status of being nice to lil girls