@ajay.vasudevan I think you are misunderstanding what you are seeing here - one of Cloudflare’s services is that we can be your authoritative DNS provider for your domain.
Anyone can attempt to add a domain to Cloudflare, but they will not be able to change your real DNS records unless they have access to switch your domain’s name servers at your domain’s registrar. Without this, your domain’s DNS will be handled by your current DNS provider (e.g. whichever name servers you are pointing your domain to at your registrar) and if you are already using Cloudflare, it will be using the DNS configuration in your account and not anyone else’s.
In your case, your NS currently are:
😋 $ dig +short NS imagen.ai
Ray / Vera should be the NS assigned to you in your account. Anyone else signing up will get assigned a different set of NS and only if & when the name servers are switched at the registrar, would anyone have control over the DNS.