1) In Kill Wizard, there are mages and anti-mages, while in here there are the two workshops. There is any relationship between the groups of both manga? ( TBH I would not surprised by any of the possible answers )
2) Kill Wizard actually has a founding mithology of how magic came to the world ( in resume God crated nine sages and those nine sages managed to kill God by use of magic. But apparently 3 angels came out of God's corpse to stop the misuse of magic ... yeah, exactly ). I have a very sneaky suspicion that Evermillion has something to do with that mess ( maybe Alcina as well ) ...
3) After reading the 2nd chapter of Kill Wizard, it is quite clear to me that Kagari is not a "Fire Witch" like people call her in this manga, but actually someone suffering from the same condition than Rhodo in Kill wizard, the Salamander curse ... a nice condition adquired by someone that survived a spar with a Dragon and that had blood of it mixed with their own. In fact the only diference between Rhodo and Kagari in that regard is that Kagari can somewhat control the flames in the present ( given the state of her cell in the Kagari household in the past, I have my doubts she could control them at that time ) and that Kagari does not look to be in perpetual pain ( but then again Rhodo does not display much of it either ).
So, either the Kagari household found a survivor of a dragon attack and kept it in a basement as a last resort weapon, dropped children on dragons until one survived ( and kept it in a basement ... ) or injected children with dragon blood until they had one alive with the curse and kept it in a basement ... Well, neither option is exactly palatable, but that has some implications for the story ( maybe there are others with the same curse ... and also what wil happen if Kagari loses control of it :/ )