Well DNS is just a lookup, not a redirect, and it can only say this hostname is at this IP address. So as such with just DNS you can not say www.aysteria.net --> 123.45.678:69.
However Cloudflare does have ‘page rules’ and you could get your desired result by creating a page rule for ‘www.aysteria.net/’ which says redirect to ‘http://123.45.678:69/$1’. The '’ and ‘$1’ just mean that whatever page is visited on www.aysteria.net is passed to the IP address call too.
Note that www.aysterai.net must be being proxied by Cloudflare (that is, set to ‘orange cloud’) for this to work.