Ok, let's see what we can do. Note that having all-male Pokemon makes you very vunerable to a female with Attract:
Sceptile @ Petaya Berry
EV: Speed, Sp Att
Nature: + Speed/Sp Att, - Att
Leaf Blade
Dragon Claw
Crunch/Quick Attack
Thunderpunch/HP Fire
Shiftry - I've just started using one of these, and they're not bad:
[email protected] Berry
EV: Att, minor Speed, Sp Att
Sunny Day/Quick Attack
Solarbeam/HP Grass/Giga Drain/HP Dark
Shadow Ball
Explosion
Never try to tank with Shiftry, it doesn't have the defences.
Grumpig - Magic Coat has it's uses, but I gotta change the rest:
Grumpig @ Leftovers/Choice Band
EV: HP, Def, Sp Att, minor Sp Def
Nature: + Def/Sp Att, - Att
Psychic
Light Screen/Reflect/Rain Dance
Magic Coat
HP Water/Trick
Rain Dance in case you run into Houndoom/sunnybeamers. Or you can just Trickband any special sweepers.
Flygon - very cool Pokemon. Let's make it cool as possible:
Flygon @ Lum/Liechi/Petaya Berry
EV: Att/Sp Att, Speed, minor Def
Nature: + Att/Sp Att/Speed, - Sp Def
Earthquake/Dragon Claw
Rock Slide/Flamethrower/Fire Blast
Quick Attack/Crunch
HP Grass/Giga Drain/Dragon Claw
Flygon can do physical or special attacks here, fairly versatile Pokemon. Watch out for that Ice weakness though.
Walrein @ Leftovers/Chesto Berry
EV: HP, Sp Att, Sp Def, minor Def
Nature: + Sp Att, - Att
Surf/Hydro Pump
Ice Beam
Encore/Rest/Roar
Body Slam/Toxic/Rest
Chesto Rest with Toxic, or throw on Encore for some annoyance factor. I also added Roar as an option, since you lacked a hazer.
Banette - all about physical for Banette:
[email protected]/Liechi Berry
EV: Att, Speed, minor Def/Sp Def
Nature: + Att/Speed, - Sp Att
Will-O-Wisp
HP Fighting
Shadow Ball
Knock Off
Knock Off ruins a tank's day, and the rest is just all round damage for Banette.