>>283101083
>Piccolo were a mentor characters yet didn't get killed off
Pic related. Which brings me to:

>>283101297
>One of them were going to get killed
Not necessarily, it's a battle shonen. They could run away from a supposed fight to the death, you could have a fakeout death, one of them dies but it's temporary, one of them gets possessed or mind controlled and the fight ends, someone else interrupts the fight, among many other possibilities.