Steelswarm Caucastag [HA05-EN050] Secret Rare WTR167-R but what is the ghost

but what is the ghost trying to tell you exactly

If a monster is Fusion Summoned while you control this monster (except during the Damage Step): You can discard 1 card

Set: Extreme Force Card type: Field Spell Rarity: Ultra Rare All "Rokket" monsters on the field gain 300 ATK/DEF

If you're looking to maximize your mash-up

Steelswarm Caucastag [HA05-EN050] Secret Rare WTR167-R but what is the ghostSet: Hidden Arsenal 5: Steelswarm Invasion Card type: Effect Monster Rarity: Secret Rare Attack: 2800 Defense: 0 When this card is Tribute Summoned by Tributing 2 "Steelswarm" monsters: Activate 1 of these effects. Destroy all monsters on the field, except this card. Destroy all Spell and Trap Cards on the field.