It is not a vps inside of a vps, your funny lol. Your joking. if you don’t know by now what I am talking about that is outstanding.
think of what virtualbox is for and tell me again.
here is what they said about kvm with virt-manager to be installed on linux, it does not say anything about needing a dedicated server. and contabo has the setup on vps with proxmox kvm they setup kali on it. but here is the alternative to proxmox it’s virt-manager with kvm and the article to describe what I mean.