Here's what rhymes with ultimately.

Consider these alternatives

thus / us indeed / need prove / use however / never therefore / wherefore would / could could / good unfortunately / fortunately proved / used because / laws if / is nevertheless / less might / right though / so effectively / respectively that / at either / neither believe / leave unlikely / likely soon / moon reason / season it / which so / though meant / went whatever / never never / ever seems / means decided / presided