Yes.
It's better to have a high Typhlosion level
Tyranitar
Depends on the moves you teach them
Garchomp is a dual-type Dragon/Ground pokémon.
Yes
Garchomp is probably a better Pokemon. Although ho-oh is a legendary, Garchomp has better stats. It is quicker with higher attack.
Yes.
For me best pokemons are: arceus charizard darkrai garchomp feraligatr giratina lugia ho-oh mewtwo typhlosion
It's better to have a high Typhlosion level
I think you need either a flying or electric pokemon. Zapdos is a good choice, if you can get it.
kind a
Typhlosion is a Fire type pokemon.
Tyranitar
Depends on the moves you teach them
garchomp
Garchomp, for he is a dragon type and he has ice, fire, dragon, normal, and a lot more different typed moves rather than hippowdown,