Soul Latcher

[BPHSCHIP]

 

When this card should be sent to the Graveyard, you can equip this card to a monster you control instead. (This card is treated as an Equip Spell Card.) If the monster equipped with this card is destroyed, Special Summon this card onto your side of the field. If this card is Special Summoned this way, banish it when it leaves the field. 

[Flash Flyer - Sakura]

If this card would be sent to the Graveyard: You can equip this card to a monster you control instead. (This card is treated as an Equip Spell Card.) When the monster equipped with this card is destroyed: Special Summon this card. If this card is Special Summoned this way, banish it when it leaves the field.
 
And exactly how does this play out if you use this card as Synchro Material (and did not SS it by its effect); even though it's optional?
 
In other words, it Special Summons itself automatically when the monster it's equipped to goes; but also keep in mind that non-destruction effects are relevant lately and bypass this card's effect. Otherwise, it's a regenerative Level 3 Tuner to make Synchros with; or some Rank 3 Xyz of your choice.

[Maeriberii Haan]

If this card would be sent to the Graveyard: You can equip this card to a monster you control instead. (This card is treated as an Equip Spell Card.) When the monster equipped with this card is destroyed: Special Summon this card. If this card is Special Summoned this way, banish it when it leaves the field.
 
And exactly how does this play out if you use this card as Synchro Material (and did not SS it by its effect); even though it's optional?
 
In other words, it Special Summons itself automatically when the monster it's equipped to goes; but also keep in mind that non-destruction effects are relevant lately and bypass this card's effect. Otherwise, it's a regenerative Level 3 Tuner to make Synchros with; or some Rank 3 Xyz of your choice.

 

In that case, it would miss timing due to being a when....you can effect. Though, with your fix, I think the card would be able to equip itself to the Synchro Monster summoned.

 

Personally, the concept itself is quite interesting, due to Zombie's wealth of support. It's like another flavor of Vylon Prism, but I think there's no harm in making it able to trigger whenever the monster equipped with this card is removed from the field, since it doesn't actually have ways to summon itself to the field in the first place.