Obtained in a link trade. Suspiciously says "Apparently met at Lv. 57 In the Pokemon League" holding a sitrus berry. Exactly like the elite four guy. It was caught with a masterball. Hacked? Maybe but still tough.
Physical sweeper. Dragonbreath's effect (may paralyze) saved him in the battle with Cindy's Garchomp. Paralyzed and Supereffective. Don't mess with him. He took down the champion.
Prepare yourself for a mighty wall of text.
Rotom needs to be changed to a Timid nature, with the following EV spread: 252 Sp Atk, 252 Spe, 6 HP. Rotom also wants the following moves: Shadow Ball, Tbolt/Discharge, Will-o-Wisp, and Light Screen. And since he's your lead, give him a focus sash.
Lapras needs to be changed to an adamant nature, and given the following moves: Dragon Dance, Waterfall, Ice Shard, Return. It wants the following EV spread: 32 HP, 252 Atk 224 Spe, and given leftovers as it's held item. Lapras would also love it if you would change her ability to water absorb by rebreeding.
Clefable wants a Quiet nature, and also wants the following moves: Double Edge, Fire Blast, Grass Knot, Softboiled, and for the love of all that is good, change it's ability to magic guard through rebreeding, and give it a life orb.
Drapion is a terrible physical wall, but a threatening physical sweeper. Change it to a jolly nature, with these EV's: 252 Atk, 4 Def, 252 Spe, and give it the following moves: Cross Poison, Night Slash, Swords Dance, and Ice Fang/Earthquake. Also give it a life orb to increase it's power output.
Steelix on the other hand, makes a fantastic physical wall. Give it a relaxed nature, with these EV's: 252 HP, 120 Atk, 136 Def and give it the following moves: Stealth Rock, Earthquake, Gyro Ball, Roar, and give him a nice big plate of leftovers.
Lucario looks like he wants to be a mixed sweeper, so here's the set i'd use. Lucario @ Choice Scarf @ Mild nature @ 216 Atk, 252 Spe, 40 Sp Atk @ Close Combat, Dark Pulse, Ice Punch, Psychic/Earthquake
Those are my suggestions. The team in it's current state, i'd rate it with a....2 but if you make those changes, i'd give you a full 5/5