Playing the game with an underleveled team

Unfortunately, I was getting too much EXP for this game to be a challenge.

I started with a Cyndaquil, a traded Scyther and a traded Croagunk. I'm only going to post the Pokemon that actually battled, the others weren't needed or are HM slaves.

Falkner: L10 Cyndaquil, L10 Scyther.
Bugsy: L13 Cyndaquil, L13 Scyther.
Whitney: L23 Croagunk.
Morty: L30 Scyther, L27 Espeon (from a L1 Eevee I traded in).
Chuck: L32 Espeon. Defeated him with 4 Confusions.
Jasmine: L34 Espeon.
Pryce: L38 Espeon, L36 Magneton.
Clair: L46 Espeon, L44 Magneton, L45 Scyther.
Kimono Girls: L50 Scyther. Took 'em all down.

E4: L58 Espeon, L57 Scyther, L46 Magneton, L45 Lugia.

Espeon's best asset: High Speed and Special Attack with Confusion, then Psybeam and now, finally, Psychic.
Scyther's best asset: High Speed and Attack with X-Scissor, Night Slash.
Magneton's best asset: High Defense with Magnet Bomb then Mirror Shot, Thundershock then Discharge, Thunderwave.
Lugia's best asset: Aeroblast and stalling with Fly (dodged Lance's Dragonite's Outrage).

I'm building a Staryu into a Starmie at the moment, which will accompany my Espeon, Scyther and Magneton.