I feel that, whilst being a tad clunky, Kommo-o GX has been unfairly neglected in the current meta. It has the potential to be a great card. However, it really needs the help of Steam Siege Talonflame to make it un-bad. Here's my take on the deck (and, yes, I know DDE is rotating. I couldn't make a dragon deck without it).
Pokémon: 15
4x Kommo-o-GX
3x Hakamo-o
4x Jangmo-o
4x Talonflame
Trainers: 33
4x Professor Sycamore
3x N
2x Guzma
1x Brigette
1x Olympia
1x Pokémon Ranger
1x Pokémon Center Lady
2x Rescue Stretcher
4x Choice Band
2x Field Blower
3x Rare Candy
2x Special Charge
3x Fairy Drop
4x Fairy Garden
Energy: 12
3x Lightning Energy
3x Fighting Energy
3x Double Dragon Energy
3x Double Colorless Energy
Strategy: Hope to start with Talonflame and assemble as many Kommo-o lines as possible on turn 2. Then, switch to Kommo-o and use Shred. A single Aero Blitz and a Choice Banded Shred will do 200 damage. Use all of the Fairy Drops this deck includes to make Kommo-o a tricky card to take down.
Pokémon: 15
4x Kommo-o-GX
3x Hakamo-o
4x Jangmo-o
4x Talonflame
Trainers: 33
4x Professor Sycamore
3x N
2x Guzma
1x Brigette
1x Olympia
1x Pokémon Ranger
1x Pokémon Center Lady
2x Rescue Stretcher
4x Choice Band
2x Field Blower
3x Rare Candy
2x Special Charge
3x Fairy Drop
4x Fairy Garden
Energy: 12
3x Lightning Energy
3x Fighting Energy
3x Double Dragon Energy
3x Double Colorless Energy
Strategy: Hope to start with Talonflame and assemble as many Kommo-o lines as possible on turn 2. Then, switch to Kommo-o and use Shred. A single Aero Blitz and a Choice Banded Shred will do 200 damage. Use all of the Fairy Drops this deck includes to make Kommo-o a tricky card to take down.