Yama Baylord is a proud warrior ruling over the dogs in his verse while Lion-O commands the Thundercats. Naturally such a rivalry would extend to these characters as well although their power levels are vastly separated. Yama has multiple super forms which greatly increase his power. Lion-O would not even have enough time to draw his sword. Yama Baylord wins.
DReager1.com 
My Casting Idea for ‘Thundercats’ Movie, David Corenswet as Lion-O, Phoebe Dynevor as Cheetara, Daniel Kaluuya as Panthro, Adam Driver as Tygra, Anya Taylor-Joy as Pumyra, Patrick Stewart as Jaga,
I’d definitely be up for a Thundercats movie. A lot of good things can be done with that series