Scylla, Tamer of Monsters

[Thepopon8r]

First attempt at making a card in a long while, wanted to get back into the swing of things and see what you guys think.

 

 

3 Level 4 Monsters

Once per turn, you can detach 1 XYZ Material from this card, then declare 1 Type of monster, Destroy all face-up monsters of the declared Type on the field, and if you do, you can attach 1 monster with a Level destroyed by this effect to this card as an XYZ Material. This card cannot attack the turn you activate this effect. You can only activate the effect of "Scylla, Tamer of Monsters" once per turn.

[Flash Flyer - Sakura]

Aside from maybe 'tellars and some other stuff, very few Decks nowadays even go into 3-mat Rank 4s. Given the amount of Archetypal decks, you'll probably blow up a few cards and steal an Xyz Material for yourself. With that in mind, I don't think you need the hard OPT given the conditions to summon it in the first place. A soft one is fine. 

[The Nyx Avatar]

It requires 3 Level 4 monsters and goes for mass destruction; however, the full potential is based on the fact that your opponent only controls 1 Type. Otherwise, it doesn't seem worth the effort to set up. However, it does attach one of them as an Xyz Material, for what it's worth. Though, it's honestly more worth your Materials than Number 91: Thunder Spark Dragon.