Easy answer they don't. I don't know what crazy stuff the putted in Budokai 2 but in the series that never happened. They never even knew how to do the fusion.
The Z fighters are all the characters from DB like Yamcha, Tien, Krillin, Goku, and all them
To unlock Yamcha in game cube budokai 2, you have to defeat Nappa with Tien on stage 1 (Dragon World Mode)
No because even though he never knew his brother after a few years, Yamcha is not Goku's brother
Edited episode 108: Goku's Special Technique. He says this when hes explaining to Vegeta, Gohan, Piccolo, Tien, Chiaotzu, Krillin, Yamcha, Bulma and Puar how he escaped planet Namek as it was exploding.
Tien died once
I think Tien is stronger compared to Yamcha.
Yes and they became Tiemcha. They are even stronger than Gogeta. I don't know what that guy is saying, but in the manga/anime they never fuse. They only fuse in the games.
Yes goku and vegeta, tien and yamcha............and thats all ohhh and goten and trunks
No! Tien and Yamcha stopped fusing cuz they sucked!
Tien and yamcha fusion in the game dragonball budokai 2 or 3. He looks like yamcha except he has 3 eyes and new clothes
The Z fighters are all the characters from DB like Yamcha, Tien, Krillin, Goku, and all them
They were never taught it but if they were that would've been awesome
(Yamcha doesn't fight Recoome.) Spoiler(if you don't want to know): Yamcha,Tien,and Chiaotzu died on Earth when fighting Nappa and they were sent to King Kai. If you want to see the full fight, check out this link http://www.youtube.com/watch?v=lV_8t0lL_Vw&feature=related
To unlock Yamcha in game cube budokai 2, you have to defeat Nappa with Tien on stage 1 (Dragon World Mode)
goku + vegeta,yamcha+ tien,cooler+frieza,super 17+cell,and majin buu+janemba
To be honest im not sure, but they sorta did that in dbz budokai 2, where you can fuse tien and yamcha, goku and hercule, and super buu absorbs cell and frieza, but i don't think theyll make a game where each character can fuse with eachother, for an example a fusion between vegeta and frieza sounds cool but stupid
I believe its Goku. But there is a few hero's to.its piccolo,vegeta yamcha tien goten krillin android 18 trunks. that's all the hero's in the series