Symph Amplifire

Field Spell

Each time an effect of a "Symphonic Warrior" card is activated, place 1 Symphonic Counter on this card when that effect resolves. All "Symphonic Warrior" monsters on the field gain 100 ATK for each Symphonic Counter on this card. Once per turn: You can remove 5 or 7 Symphonic Counters from your field; apply this effect, depending on the number of Symphonic Counters removed.
● 5 Counters: Inflict 300 damage to your opponent for each "Symphonic Warrior" card on the field.
● 7 Counters: Banish cards your opponent controls and/or in their Graveyard, up to the number of "Symphonic Warrior" cards on the field.

Rulings – Yugipedia

Printings:

Raging Tempest: RATE-EN092 (Common) - 2017-02-09
2017 Mega-Tin Mega Pack: MP17-EN234 (Common) - 2017-08-24
OTS Tournament Pack 19: OP19-EN026 (Common) - 2022-06-15
OTS Tournament Pack 19 (POR): OP19-PT026 (Common) - 2022-06-15

Prices:

Cardmarket: 0.02 €
TCGplayer: $ 0.10