The general idea behind the deck is to evolve your 4 star monsters with Insect Imitation into your Millenium Scorpion or Grasshopper. Cards like trap jammer is used because once you get your strong monsters out you want to make sure they stay out, you don't want to be stopped my Mirror Wall because the comeback factor is not very strong in this deck (if you already used your insect imitation). Using cards like Blue Dragon Summoner and Emissary of the Afterlife lets you use Insect Imitation on a 4 star monster and use their effect to add Warrior Dia or Jerry Bean to your hand from your deck, essentially thinning your deck. This on top of the fact that you use Insect Imitation in order to drag a strong monster straight from your deck on to the field allows you to thin your deck of monsters, always having something to play and preferably drawing into your support cards.
The ideal game would be you opening with Blue Dragon Summoner, Insect Imitation, 1 Trap Jammer and then Preferably Mirror Wall/Enemy Controller/Windstorm. Then you would want to draw into Electro in order to lock down his traps during your next turn and take over the game.
Sadly this deck is pretty weak against Relinquished as you rely on defending your strong 5 star monsters, which is why the 2 Twisters is a must have in the deck. If you want to shave the deck down to 20 cards then I would probably remove 1 insect imitation and 1 Warrior Dia, but the deck works really well at 22 cards imo.
TLDR; Use Insect Imitation to get out strong monsters and run over your opponent. Weak against Relinquished.