Yeah if Kintoki wins or even makes this close I just can't take Odin seriously as 'The Final Bad Guy' of the series. If they bring in a new character barely mentioned as the final villain? Even worse.
Remember that the "Odin" Kintoki is fighting is actually a "clone" of the "Primordial God Odin." Likely, no matter which side wins the tournament, the Water of Life will be created and Yggdrasil will be released. I expect Ymir, Satan, Chaos and PG Odin will be the four opponents that the survivors of both sides will need to face together.