hey my name is cheezstik and this is how to get an easy beat in baby tower.
all u need to do is go to any place (except mewtwos lair)and keep catching pokemon.
once u have 6 lvl 5-6 pokemon goto set moves.make 1 half of ur team have the moves:

bite        (type:dark)         
giga drain  (type:grass)
phsycic     (type:phsy) 
double kick (type:fite)

and for the other  half have the same moves except replace phsicic with flamethrower.
make one of ur pokemon with flamethrower ur starter. then goto battle twer then clik baby
tower.the pokemon u face will always be the same. u dont hav to use my moves - u can use
ur own but i recommend mine...

here r the types:

Budew        grass and poison use anything but giga drain
Chingling    phsy   use bite  
Bonsly       rock   use giga drain
Mime Jr.     phsy   use bite
Happiny      normal use double kick  
Munchlax     normal use double kick
Riolu        fite use phsycic
Mantyke      water use giga drain

good luck and also - i think u have a slight chance to get riolu from winning this...