I have been using Ubuntu for a while but now I need to use Kali tools. I don't want to have to download a whole other distribution of linux and wanted to know if I could just download Kali straight into Ubuntu.
You can run a Virtual Machine on Ubuntu, or install the apps of Kali on Ubuntu (though I'm not sure all of them can be found easily)
https://www.google.com/search?q=kal...oid-asus-tpin&sourceid=chrome-mobile&ie=UTF-8 I found a lot of how-to-install kali tools on ubuntu (16.04-20.4), so I'd say it is doable.