1 Aqua-Type Tuner + 1 or more non-Tuner monsters When this card is Synchro Summoned: You can target cards your opponent controls, up to the number of WATER monsters used for the Synchro Summon of this card; destroy them. If this card is destroyed by battle or card effect and sent to the Graveyard: You can target 1 other WATER monster in your Graveyard; Special Summon it, but its effects are negated. You can only use each effect of "Graydle Dragon" once per turn.
and in my extra:
3 graydle slime dragon
2 white aurora dolphin
1 cryston ametrix
i would recommend something else other than the cryston, but thats all i had. 🔥 around with this deck and you'll find you can bring out 2 graydle dragon and explode their board