Ruling Rescue NRG Vs. Catastrophe

[Matryoshka]

If I have a Rescue NRG attatched to one of my Pokemon, and they Level Up to Gengar X and use Compound Pain to KO that Pokemon, would it go to the lost zone or my hand?

Gengar X:

http://media.photobucket.com/image/gengar%20card/mizu_kishi_rune/scan0018.jpg?o=5

Genprime:

http://www.serebii.net/card/triumphant/094.shtml

Rescue nrg

http://www.serebii.net/card/triumphant/090.shtml

 

[DNA]

It's the choice of whoever owns the Rescue Energy. As per the FAQ:

Q. If my Pokemon has a Rescue Energy attached, and it is Knocked Out by damage and would be sent to the Lost Zone by a card effect (e.g. Giratina LV.X's Darkness Lost, Darkrai & Cresselia LEGEND's Lost Crisis, Gengar Prime's Catastrophe), do the Pokemon cards return to my hand or do they go to the Lost Zone?

A. Since Rescue Energy and the Lost Zone-sending card effect will happen at the same time, the owner of Rescue Energy can decide which effect happens first; it is that player's choice to decide whether they go to the hand or Lost Zone. (Either way, all non-Pokemon cards are sent to the discard pile.)