Character VS Character

If you could pit two characters from two separate game series against each other in an all-out, fight to the death, no hold bars battle, who would you choose and who do you believe would win? Why would did you choose those two characters. Please try to make the characters from different series but if you can't, no biggie. Furthermore, this goes across any console, PC, handheld etc. system in the history of video games. So feel free to be creative with your choices!

Uchiha Sasuke vs Vegeta. Two cold and badass villains in an all-out fight, that'd be great!

Trevor Phillips vs Vaas, two pretty insane people, both love to kill others, could be interesting

I would pit...

AGE-1G Gundam AGE-1 Glansa VS. Slime

watching a 17 meter tall robot crush a small slime :D

I think Cloud vs Squall would be pretty dope. Squall of course has a 18 hit lionheart vs cloud's 16 hit omnislash.

One I'm sure many have thought of I'd love to see:

Ryu Hayabusa (Ninja Gaiden) versus Joe Musashi (Shinobi)

Another I'd like to see would be:

Gannondorf (Zelda) versus Magus (Chrono Trigger)

Alucard (Castlevania) vs Flandre Scarlet (Touhou).

Two vampires from 2 games. Both really strong in the magical arts.
(I'm sure I made a mistake with Alucard there o.o)

Agent 47 vs Trevor Phillips. Two complete opposites

Giga Bowser vs. Ganon (OOT).

Not even sure who would win, but it would be quite epic. :D

Ribby & Croaks (from Cuphead) vs The Battletoads, may the best frogs and/ or toads win. Good day for a swell battle.

Shield Knight (Shovel Knight) vs Vexen vs KH Goofy (All out Shield on Shield on Shields combat.)