Hallo the Great Spirit of Tricks

If this card is Normal or Special Summoned: You can make your opponent choose 1 of these effects for you to apply. You must control this face-up card to activate and to resolve this effect.
● This card gains 800 ATK for each Fiend monster in your GY.
● Inflict 500 damage to your opponent for each Fiend monster in your GY.
If this card is destroyed by battle or effect: You can send 1 monster your opponent controls to the GY. You can only use each effect of "Hallo the Great Spirit of Tricks" once per turn.