Good last pokemon! ( Light Platinum )

Hello guys! I was wondering and I have been for a while now, what pokemon should I have in my last pary slot? I'm playing Light Platinum ( the Ruby hack ) and I have these pokemon:

Piloswine - Lv53 with Oblivious ability
Swampert - Lv44 with Torrent ability
Hydreigon - Lv64 with Levitate ability ( Grinded like 4 hours for it :p )
Typhlosion - Lv46 with Blaze ability
and
Lucario - Lv46 with Inner Focus ability
+ that last empty slot

These are the pokemon I've been thinking about :
Venusaur
Drapion
Grumpig
Gengar
That psychic evolution of Eevee ( don't remember his name )
and
Drifloon (his evolution which i don't remember his name)
Raichu
That grass starter from pokemon Pearl / Diamond

I'd appreciate any pokemon you'd reccomend to my team, but most preferably a pokemon you know a trainer with pokemon around my levels can get in the Light Platinum game. ( I'm at the snow city, done nothing there yet. )

UPDATE:

I've changed some of my pokemon to this instead:

Instead of SWAMPERT, I've picked STARYU (grinding to evolve it atm)
Instead of PILOSWINE, I've picked TYRANITAR (grinding to evolve it atm)
at the last slot I've picked VENUSAUR because of its good movepool.
The rest is the same.

There's really not a good place to put this. It doesn't belong here, but it doesn't belong where normal game teams would go because I'm sure there are differences between this game and real games. The best I can tell you is to ask in the thread for it. Sorry I couldn't be more helpful!