Dark Valkyria (Starfoil) (BP01-EN152) - Battle Pack: Epic Dawn 1st Edition

This card is treated as a Normal Monster while face-up on the field or in the Graveyard. While this card is face-up on the field, you can Normal Summon it to have it be treated as an Effect Monster with this effect:
• Once, while this card is face-up on the field: You can place 1 Spell Counter on it. This card gains 300 ATK for each Spell Counter on it. you can remove 1 Spell Counter from this card to target 1 monster on the field; destroy that target.