Since it's a colorless card, it could easily slot into virtually any deck without the player having to make many sacrifices
This is enabled by a few "Morphtronic" monsters that have Special Summon effects
Sacrifice after III.) I - Gungnir - Destroy target creature an opponent controls.II - Zantetsuken - This creature gains "Whenever this creature deals combat damage to a player, that player loses the game."III - Hall of Sorrow - Draw two cards
Graveyard synergies, lifegain, and efficient creatures shine here
Besides that and a few preference choices, I don't see that much wrong with your main deck
As long as you can keep adding Genex monsters to your hand with card effects, you can keep Normal Summoning them out right away perfect for assembling powerful Synchro Monsters like Locomotion R-Genex , or the new Level 10 Genex Synchro in this set that can repeatedly negate and destroy your opponents monsters by banishing monsters from your Graveyard