Magic can kill people. Magic can set things on fire. Neither of these things is impossible, even without magic. QED.No, magic by definition can only do things that are impossible. If it's not impossible it's not magic.
Even if you were right, this would be in no way a rebuttal to my point.
I have no idea what you mean by this.Try telling that to the Red Queen.
It seems like you would agree with me that the @Henadic Theologian's assertion that Eberron's crystal sphere had "like over a dozens planes" "shoved" into it was both wrong and kinda silly. So why are you arguing with me exactly?I don't see any evidence for that. Demi- means "half" or "partial", not "inside". In the D&D sense I generally take it to mean "finite", whereas full planes are infinite. Bags of Holding do not break when you cast Plane Shift whilst carrying one. The space inside is not inside the Material Plane or it would stop working.
But for the record, there are plenty of references to demi-planes being inside other planes in the history of D&D, although most of the ones that come to mind are for older editions. For example, in the 2e version of Ravenloft, you got the maximum bonus with you sword of the planes, because you were technically in the ethereal plane. Of course, Ravenloft has changed a lot over the years since then....