Forum:Constellar Ptolemy M7

I have read the rules of constellar Ptolemy M7:

If "Constellar Ptolemy M7" is the only monster on the field, its effect can be activated and target the Xyz Material that was detached as a cost.[3]

But if is not my only monster on the field? can i target the Xyz material that i detached as a cost?

ALdo Espinoza (talk • contribs) 05:11, May 7, 2013 (UTC)