no, akame ga kill does not involve video games, however Ainz is not in the original world of the Yggdrasil MMO either.
So, you want to see how the power levels of the two verses compares?
Some time ago i made a comparison, based in the tiering system of the vs battle wiki page, in order to see how the people in Overlord would compare to other fictions.
I did the only calc available in the site for overlord and, using that as a reference, i started to assign a tier to each level. Just so you know, the calculation that right now is accepted was performed by the lich Ainz created for the war against the lizard villages and is severily overstimated.
That calc yield the power level of a level 22 character. Anyway, this is the chart i make. You must understand howerver, that in high levels thing could be really different to what i have.
This is based in the tiering system and attack potency chart of the vs battle wiki.
Tiger: High 9-C; < Climb: 9-B < Zaryusu: low 9-A < (Wall) < Zero: 9-A < Gagaran: High 9-A < Brain: barely 8-C < Gazef: 8-C < Hamsuke: 8-C < Clementine: barely High 8-C < Gazef (with equipment): high 8-C < Clementine (with equipment): barely 8-B < (¿level 35?) 8-B < (¿level 40?) High 8-B < (¿level 45?) 8-A < (¿level 50?) High 8-A < (¿level 55?) low 7-C < (¿level 60?) 7-C < (¿level 65?) 7-C < (¿level 70?) High 7-C < (¿level 75?) Low 7-B < (¿level 80?) 7-B < (¿level 85?) 7-A < (¿level 90?) High 7-A < (¿level 95?) 6-C < (¿level 100?) High 6-C/6-B
If we compare this to the power levels of the akame ga kuri verse, we see that their stronger fighters (Esdeath, the protegonist and akame) are 7-A in their strongest (end of the series).
This power level, i think, is based in the fact that they should be comparable in power to a beast who was way bigger that some mountains. So, by sheer size alone, it should be able to generate an energy output that give such a beast a 7-A tiering (100 megatons to 1 Gigatons.)
Based in my rough estimation of the power level of the overlord verse, Esdeath, Takumi, Akame and a couple of other puople should be, in their strongest, between level 85 and 90 in overlord terms.
Esdeath have a feat of environmental damage that reached 6-B, however, the enormous blizzard that she generated is not something that can be used in combat (i think).
Another thing to consider, is that overlord character, like Ainz, have hax abilities very superior to the ones of the akame ga kiru verse. I am talking about magic, death magic, and time stop among other things. Even if Esdeath seems to have an ability to stop time, Ainz is famous for his "countermeasures against time stop". Sadly, the akame ga kiru characters don't seem to have countermeasures against this hax.
Also, a collector like Ainz with the aid of a tamer like Aura, could have an army composed of the crazy beast from the akame ga kiru verse.
Though i haven't revised the calcs, and i don't know/remember much about the akame ga kiru verse, the rest of really powerful characters (night raid, jeagers, wild hunt, Three beasts, Rakshasa demons...) seems to vary from low 7-C to low 7-B (level 55 to 75 in overlord standards).
The rest of not as powerful characters should be vastly inferior to the ones mentioned above. I would say that the strongest of these characters should be able to fight a death knight (defense of a level 45 monster) in roughly equal terms.
Of course, Ainz can make hunderds of Death Kights and these characters in the akame ga kiru verse seems to be reallly limited in number.
Anyway, with world class items and level 100 people the Akame ga kiru verse is inferior to Overlord and their "unfair" abilities. However, is not a difference like the one between the humans of the Kingdom and Nazarick.
That depends heavely on what do you want to write.
However, i think that it could work yes.
The introduction of Nazarick will change the Akame ga kiru history depending in what you want to do.
One option could be for Nazarick to have arrived more than 1000 years ago and be connected to the foundation of the Empire. In that case, the history could begin with the Great Tomb of Nazarick "awakening" because some stupid action performed by some tomb raiders or whathever other reason (a prophecy/ancient fable from the Empire for example). Displeased with the path that humanity have taken, he desire to recuperate the Legendary class items (teigu) that he lend to humanity 1000 yeard ago and reform the Empire to create his Utopia.
Another option is to arrive suddenly in the "present" moment. There are plenty of places in which we could locate Nazarick based on the akame ga kiru wiki.
i like the way you think!
Anyone can always write a fanfiction of it. e.g: Akame's groups becoming adventurers that want to overthrow the evil undead king or after death everyone that died got transferred to the new world. Though, I doubt akame's swords will have any effect on undead.
i know Akame's sword can't effect corpses. also Ainz from what i've seen so far from the anime is an anti-hero at worst, so i think Ainz would overthrow the corrupt government and replace it with an atleast more tolerable rule. i doubt he would pull a Hitler.
What do you think?