How to Get Into the Tin Tower on "Pokemon Crystal"by Lindsay HowellUpdated September 22, 2017
"Pokemon Crystal," for the Game Boy Color, is similar to the "Gold" and "Silver" versions of the game, except with new features. You can catch both legendary birds from "Gold" and "Silver" in this version. You will find Ho-Oh, the legendary Pokemon who is featured in the "Gold" version, in the Tin Tower. Before you can enter the tower you need to complete several missions.
Defeat Team Rocket once and for all in Goldenrod City. The Director of the Radio Tower will give you the Clear Bell as a reward.
Head to Ecruteak City and then go north; this path leads to the Tin Tower. You will encounter the Wise Trio. Defeat all three of them and you will be able to catch Suicune. Find and capture the other two legendary beasts, Entei and Raiku by tracking their locations on your town map.
Defeat the Elite Four. Do this and then you can return to the Tin Tower to catch Ho-Oh, the legendary bird.
Go back to Ecruteak City and speak to the Wise Trio. They will see that you have defeated the Elite Four and will give you the Rainbow Wing, which you need to summon Ho-Oh back to its roosting place at the top of the tower.
Climb the tower, battling trainers and Pokemon on each floor. At the ninth floor, you come to a teleportation pad. Step on it and you will come out on the roof. Ho-Oh will appear; whittle down its health and use an Ultra Ball to capture it.