Well i'm Sinnoh rn, but yeah, the quest is a little bit too hard.. Some little changes would make it okay, like taking out one M. Poke from Hannah, or reduce the time between each battle against her.
Also, you can make the DeepSeaTooth buyable in a mall..
And last but no least, put the npcs in the RIGHT ORDER, omg it hurt so bad to pay 5k for one NPC when you're already struggling just to buy Pballs.!
Anyway, the difference between a Rattata level80 and THIS is a bit too much.
If i hadn't got lucky to find deepseatooth for 10k in 5 minutes, clamperl in 5 minutes, aswell as buying two moonstone for 10k (YEAH CUZ YOU ALSO NEED MOONSTONES) ,just had enough money to travel forth and back for the NPC'S.
And when it came to Hannah, she destroyed me first time, then i took 3 more full EV's level 100 Gyara' Gengar and Machamp, and even with 5 FULL EVS LVL 100 POKE and 7 revive and max potions, i got left with a 1hp gengar who got lucky the entire fight.
It took me 8 hours to get to Sinnoh... And i had some ressources.
Can't even imagine for a casual.