i have no clue but probally to help protect the dragonballs with shenron because goku was strong and would make a good combination so that might be why just rember goku would help shenron protect the dragonballs i think
Goku is stronger he can beat Syn Shenron even when he changes into Omaga Shenron.
No but evil shenron almost did in GT.
No, but there is one in dragon ball gt when goku and vegeta fuse into ssj4 gogeta to defeat him
goku
while training with shenron goku turned back into a grown up by shenron powers
If the fight is in the end of gt goku would win because goku was weakened by omega shenron and when vegeta came he was at full power but they could fuse. you have to be at the same amount of energy to fuse. Goku had a lowered power level and vegeta had a lowered power level which means goku is stronger.
after goku summon shenron
In the first episode of GT, Pilaf summoned Shenron and Goku showed up, scaring Pilaf. Goku hadn't noticed Shenron, and Pilaf said "I wish you were a kid again so I could show you a thing or two." Shenron mistakenly thought that was Pilaf's wish and turned into a kid.
Goku I believe
the dragon world
they fuse in episode 253 of dbz thanks for the question