Big Benkei (2) - main monster of the deck
Blue Brawler (3) - indestructible in battle
Scales (3) - Special Summonable, if the opponent controls 2 or more monsters; revives a Level 4 or lower Superheavy Samurai for Synchro or Xyz
Trumpeter (2) - Special Summonable, if you have no S/T in Graveyard; a Tuner for Syncho Summon (especially for Shutendoji we dont' have currently in TCG); if you tribute him for Benkei he can revive itself from the Graveyard
Flutist (3) - can tribute itself to Special Summon a Superheavy Samurai from the hand (→ Benkei); when a card or effect targets a Superheavy Samurai you can banish him from the Graveyard to negate the activation and to destroy that card
Gigagloves (3) - the Sylvan monster of the deck: if he is sent to the Graveyard you can look at the top 5 cards of your deck and place them on the top of the Deck in any order; can be banished from the Graveyard when the opponent declares a direct attack, excavate the top card of your Deck, and if it is a Superheavy Samurai you can add it to your hand and the attacking monster's ATK becomes 0
Soulpiercer (3) - the searcher of the deck when sent from the field to the Graveyard; can be equipped from hand (or field) to a Superheavy Samurai
Soulbang Cannon (1)- can be equipped from hand (or field) to a Superheavy Samurai and gives it 1000 DEF; can be banished from the Graveyard to negate the activation of an opponent's card effect during Battle Phase and acts then as a Dark Hole
Soulfire Suit (2) - can be equipped from hand (or field) to a Superheavy Samurai and its level becomes 5; can be discarded (during either player's turn) to protect a Superheavy Samurai from being destroyed by battle or by card effects
Soulbeads (2) - can be equipped from hand (or field) to a Superheavy Samurai and the equipped monster can't be destroyed by a card effect once per turn (each turn); can be sent from the hand to Graveyard when a Defense Position monster is destroyed by battle to revive that monster in Attack Position
Construction Train Signal Red (2) - battle hand trap; Synchro fodder
Giant Rat (2) - floater and can Special Summon Benkei
Lyla, Lightsworn Sorceress (2) - kills some S/T; to mill here is no problem → Gigagloves!
Neo-Spcian Grand Mole (1) - the deck has no CED
Genex Ally Birdman (1) - Special Summonable tuner
T.G. Striker (3) - easy Special Summonable; easy access to the Naturia Synchros
Effect Veiler (3) - effect negation is always good; tuner if needed
Gorz the Emissary of Darkness (2) - battle hand trap; token is useful for Synchros
Extra Deck:
no explenation nedded; i would replace the 2nd Goyo for Shutendoji
Any suggestions to improve the deck?