Maestroke the Symphony Djinn

The monster effect "Once per turn: You can detach 1 Xyz Material from this card, then target 1 face-up Attack Position monster your opponent controls; change that target to face-down Defense Position" is an Ignition Effect. (Detaching 1 Xyz Material from this card is a cost to activate this effect.)

The monster effect "change that target to face-down Defense Position" is an effect that targets 1 face-up Attack Position monster in your opponent's Monster Zone.

The monster effect "While this card is face-up on the field, if a 'Djinn' Xyz Monster you control would be destroyed, you can detach 1 Xyz Material from that monster instead" is a Continuous Effect. (This can also be applied during the Damage Step.)

The monster effect "if a 'Djinn' Xyz Monster you control would be destroyed, you can detach 1 Xyz Material from that monster instead" can also be applied when "Maestroke the Symphony Djinn" itself would be destroyed.