When I used this card’s <Delay> effect to delete 1 of my Digimon with an [On Deletion] effect and play [Kimeramon] or [Millenniummon] from the trash, I declared an Assembly for the card to be played. If I place the deleted card for the Assembly at such times, can I activate that card’s [On Deletion] effect?
Show ruling
No, you can't. When a card with an effect that's pending activation leaves its current area while activation is pending, the effect can no longer be activated.
Source: P-205 Insane Synthetic Monster