Sounds reasonable, so Tom could actually be greater than Morgoth and Manwe. Since he is one of the unknown ainus like Ungoliant the valas did not know of him and his power. I really like the idea of these outcasts, great powers that doesn't fit in. However Tom can't be greater than illuvatar so for what reason did illuvatar create Tom other than to sing arda into existence? Yeah I know these questions have been asked before, I'm just bored and it's so fun to read your complex replies.
He was there before the dark lord entered, that means for whatever reason he sneaked in before the other great ainur did. What did he do in a empty arda?