Celio is a t ONE island he's the guy standing next to the trading machine at the Pokemon hospital
i think you can get timer balls on two island after you Complete Celio's Network Machine
visit all the different islands and give celio the ruby and sapphire.
You can do this after you find the Ruby and the Sapphire for Celio in Pokemon FireRed. then you can trade with Ruby, Sapphire and Emerald.
Find the ruby inside mt ember give it to celio and he will let you go to islands 4-7.
give it to celio
You give it to Celio
he is in one island in the hospital.
Give it to Celio on one island.
You get a map from Celio, on one island.
yes
in the dotted hole on island 6
you can catch mewtwo at cerulean cave
find the ruby and give it to celio.
but before this, you must have defeated the elite 4
Give it to celio in 1 island
go to one island and talk to celio