Dragard

The monster effect "①: When this card is Normal Summoned: You can target 1 Normal Monster with 1000 or less ATK in your GY; Special Summon it in Defense Position" is a Trigger Effect. (This effect targets 1 Normal Monster with 1000 or less ATK in your GY.)

The monster effect "②: Once per turn: You can Tribute 1 Dragon monster you control, then target 1 face-up monster you control; that monster becomes Level 8, and if it does, it gains 800 ATK until the end of this turn" is an Ignition Effect. (This effect targets 1 face-up monster in your Monster Zone. However, you cannot target an Xyz or Link Monster.)

The effect that makes the monster become Level 8 and the effect that increases its ATK by 800 are both effects that are applied until the end of the turn in which they were activated.

When activating the monster effect "that monster becomes Level 8, and if it does, it gains 800 ATK until the end of this turn," you Tribute 1 Dragon monster in your Monster Zone as a cost. (You can also Tribute a face-down Defense Position Dragon monster. Additionally, you can Tribute "Dragard" itself.)