i would have to say tyranitar but, its a matter of opinion
Tyranitar ;prime
Tyranitar
no you should not.
that depends on your personal preference i personally think tyranitar over aggron
its the same
Second question: Latios
I say aggron because it has much better defense and in mega evolution it has ultimate defense
Yes exept use latios instead of rayquaza and latias instead of lugia
Garchomp Because Garchomp is a Dragon type. Garchomp knows Better attacks than tyranitar . He also has more hp than tyranitar if the trainer diddn't put Hp ups.Tyranitar is still good but not as good as garchomp. They both have to be level 100 to make this a good answer.
I would suggest getting a tyranitar or umbreon instead of sableye. Also the bastiodon should be switched out with aggron. Also a fire or dragon type would be handy I beat soulsilver with a Feraligatr Tyranitar Dragonite Sceptile Magmortar and Ampharos.
latios is stronger offensively, and latias is stronger defensively.
Yes that is a great team! but I would just add in a Raichu because it hase Thunderbolt which could make a Gyardos faint.