[Ruling] Yu-Gi-Oh! - Neo-Spacian Grand Mole vs. Ally of Justice Catastor

[Koby]

This came up in a duel between me and Bardon. Well it didn't actually happen but we were questioning it thinking it may... so I decided to ask DN staff about it.

Neo-Spacian Grand Mole

If this card battles with your opponent's monster, you can return both monsters to their owner's hands at the start of the Damage Step (without damage calculation).

Ally of Justice Catastor

If this card battles a non-DARK monster, destroy that monster without applying damage calculation.

On DN the effect is written a little different: If this card attacks or is attacked by a non-DARK monster, destroy that monster at the start of the Damage Step (without damage calculation).

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Question: How would this play out if they battled? Would Mole get destroyed or would Mole return to hand and Catastor return to Extra Deck, or would Mole get destroyed and Catastor return to Extra Deck... etc?

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Answer: Mole wins. Castator's effect is mandatory, while Mole's is optional (look at the text). So Catastor's mandatory effect goes first on the chain, and Mole's optional effect is second on the chain. As always the chain resolves backward.

Chain Link 1 - Catastor (mandatory)

Chain Link 2 - Grand Mole (optional)

Resolving backwards, Mole sends both monsters to the hand and Extra Deck respectively, then Catastor cannot destroy Mole because it is no longer on the field.

[Xitrons]

I will confirm this is correct.

[Seabs]

Good to know, as both cards are incredibly pesky. I didn't know that optional effects occurred after mandatory ones in terms of chain development.

[Darvius@msn.com]

This is true with it being written differently. However, when in a physical game, the effect of Catastor happens before the damage step and thus goes on the stack and resolves before the effect of Mole is even concidered. Thus making Catastor win.

[eduardo077]

Ha had this problem a couple of times and decided to play R/P/S for who got the effect, but now i know