https://www.db.yugioh-card.com/yugiohdb/faq_search.action?ope=5&fid=14088&keyword=&tag=-1

https://www.db.yugioh-card.com/yugiohdb/faq_search.action?ope=5&fid=22941&keyword=&tag=-1
Adding material is a effect that affects the Xyz Monster.

https://www.db.yugioh-card.com/yugiohdb/faq_search.action?ope=5&fid=19250&keyword=&tag=-1
It still applies when the Xyz is face-down.

Fix won't disable spell & trap

fix: it can target the monsters like Gem-Knight Pearl.

1. It does not need SetRange()
2. If it is a Condition Effect, it does not need EFFECT_FLAG_CANNOT_DISABLE+EFFECT_FLAG_UNCOPYABLE.

https://www.db.yugioh-card.com/yugiohdb/faq_search.action?ope=5&fid=18253&keyword=&tag=-1