My third blog, unlike the previous two, I did the calc myself.
Feat[]
Feat happens here. Isabeau encase the entire France within her barrier the moment she became Witch. Using the same formula like in this blog, just gonna replace the number with 452 since Kal and Dodo said that is France's Radius.
Math[]
Yield = ((452:0,28)^3)*0,5 = 2103348396 kilotons
Scaling[]
This only affects Corbeau's Dream World and Tart's Dura.