Last Man Standing

Name: Kane Blueriver Tenchi Masaki
Birthdate: May 30th, Age 20 April 24th, Age 17
Height: 5 feet 8 inches 5 feet 2 inches
Space ship: Avatar of the God(dess) Volphied, the Swordbreaker Depending on who he's in good with that day, Ryo-Ohki or Ryu-Oh
Grandparent's Claim to Fame: Grandmother was the chosen representative for Volphied. Grandfather is Crown Prince of Jurai
Number of annoying girls put up with on a daily basis: 2 *3 if you're using the manga* 6 *7 if it's Tenchi in Tokyo*
Weapon of Choice: Remarkably light-sabre-ish Psy Blade Remarkably light-sabre-ish Master Key *or Light Hawk Blade, depending on whether it's OAV or Universe*

The Battle: What we're looking at here is two skilled swordsman ready to duke it out. It wouldn't be too hard to find a reason for them to fight, either. Alls we'd have to do would be to get the Universal Guardians *or whatever* to send Kane on a trouble contract on Ryoko. Easy enough. Then, when he tries to arrest her, we'd get to watch the fur fly. Doubtless, Tenchi wouldn't be havin' none o' that crap, and a lovely battle to the death would ensue. ^_^

The Blow by Blow: In single combat, the battle is pretty clear cut and drawn. Tenchi and Kane would duel using their remarkably similar weapons. The only problem with this would be for poor Tenchi. Kane is lightyears ahead of him in the dueling department, having studied under arguably one of the best swordswomen in his universe. He has several years experience in advance of Tenchi, and his weapon is actually reliable. In a duel, Kane whips Tenchi's pasty ass, hands down.
However *there is ALWAYS a however*, it's likely this would not be a clear cut, easy duel. In Tenchi's case, everybody from Yosho right down to that old woman who runs the hot springs would jump in, causing general pandemonium to ensue. Yosho, were he to duel Kane, would likely be a match for him, if not simply the victor.
Then we get into the much nastier arena of space combat. Ryo-Ohki *which was created by a Goddess* and the Swordbreaker *which IS a Goddess*, could very likely go toe-to-toe with one another. While neither one was honestly built to kick much ass, there would be property damage on a grandiose scale.
I see this eventuality rather unlikely. In all likelyhood, Canal would probably just cuddle Ryo-Ohki *in cabbit form, natch* and laugh when Millie and Ryoko started duking it out.
Which brings us to another rather nasty eventuality: the WOMEN getting involved. Nothing in this universe *or any other, for that matter* is scarier than watching a Tenchi Muyo catfight. Chances are, Millie will be the poor, unfortunate, DUMB soul who picks a fight with Ryoko. Of course, the one who would probably be a better match for her would be either Mihoshi or Sasami, but this IS Millie we're talking about here.
Needless to say, while Millie is running in fear from Ryoko, Ayeka and Canal will be sitting on the sidelines, cheering them on.
"Give her a right! Shoot her! SHOOT HER!"
"Don't take that from her! Beat her to a pulp!"
"Just who are you rooting for here, anyway?!"

The Winnahhhhhh...
Duel *single combat*: Kane. Tenchi can't keep up with him. Maybe after a few more years of practice...
When *not if, mind you* all hell breaks loose: Darkstar. Let's face it, no one else is gonna come out of this alive. This is quite possibly the end of the universe as we know it.