Removed RB05 It's Worse
This card also combos well once you have one of your synchro Tenpai monsters on the field, as you can destroy Sangen Summoning to double the attack points of the Synchro Monster
A lot of balance and care goes into choosing the cost of a card, more than I can express here, but looking for similar effects on existing Magic cards can give you an idea of a fair costfor example, a ramp spell that puts two lands into play ought to cost 4 mana, per Explosive Vegetation
Surge, Erika, or similar cards to execute key strategies, Shadowy Spellbind poses a major challenge, disrupting their momentum and limiting tactical options
It was not born naturally
The set carries strong nostalgia and is building momentum heading into the broader Scarlet & Violet Trainer's Pokmon era