He is in a cave on the Route west of Lilycove City go up those one stairs near the girl that gives you Wiki Berries and keep going up until you find the cave.
To get Registeel you would have gotten the level 100 Regegigas from a wirerless event or migrate it from saphire, ruby, or emerald.
you need regice, regirock, and registeel from Saphire/Ruby/Emeraled
go on youtube and type in ... *how do you get the rgis on pokemon saphire ruby and emerald vershion.
You cant get registeel in pearl the only way to get it is by eighter using action replay or transfering from ruby or saphire:)
you need to migrate the 3 regi's (regice, registeel and regirock) from ruby/saphire/emerald to your game and have them in your party. then you can enter the temple.
they are the three legendary pokemon of rock, ice and steel. they are know as regirock, regice, and registeel. you can find them in Ruby, Saphire, and Emerald.
I used my starter pokemon(whitch was blaziken) My regi rock registeel and regi ice( from saphire) a tyranitar, and a castform.
First, you must complete the puzzle on Route 134 and the Sealed Chamber. After that, three mounds across Hoenn will open up to show a hidden cave. Registeel resides in the Ancient Tomb on Route 120. However, be warned - there is Braille there.
The legendary Pokemon in Pokemon sapphire are groudon, rayquaza, Kyogre, Regice, Regirock and registeel EDIT: No you cannot unlock/get Groudon, Rayquaza, or the Regi's.
Jon Saphire's birth name is Jonathan Saphire.
Christopher Saphire's birth name is Christopher Donald Saphire.
You can catch Rayquaza and i think groudon and kyogre to but im not sure. and if u have the eon ticket u can get to latios or latias (depends on wich game u have) thats all i know bye I KNOW more than that though. You can also catch Regirock, Registeel, and Regice.