The team was excited and enjoyed almost all of this playtest
UR Ultra Rare Dark Necrofear X DARK Level 8 [ FiendEffect ] ATK 2200 DEF 2800 Cannot be Normal Summoned/Set
Outside of that specific synergy, Toxrill is still very good
Alternatively, where it is legal "Kashtira Arise-Heart", supplemented by "Outrigger Extension" and "Goliath", could take the place of "River Stormer" as an endboard piece in this combo through the implementation of "Scrap Recycler" (as the "Gear Gigant X" search/"Platinum Gadget" summon, sending "Harvester"), "Infinitrack Trencher" (in place of "Tunneler") and "Infinitrack Crab Crane" (searched via "Harvester")
Maliss Chessy Cat X DARK Level 3 [ Cyberse / Effect ] ATK 1500 DEF 300 Any monster destroyed by battle with a "Maliss" Link Monster that points to this card is banished
In any case, I should have written the cards' last line like "You can only use each effect of "name-of-spell" once per Duel."