Forum:Lancer Archfiend

Just a quick ruling question. I've got DNA Surgery on the field treating the field as Spellcaster, and a Red Nova Dragon on the field just affected by Diffusion Wave-Motion. If I use the effect of Lancer Archfiend, which gives one face-up monster piercing, how long does Lancer Archfiend's effect last?

''Once per turn, when a monster you control declares an attack targeting a Defense Position monster your opponent controls, you can activate this effect. If you do, during this battle, if the ATK of the attacking monster is greater than the DEF of the Defense Position monster it battles, inflict the difference as Battle Damage to your opponent. '' Potterfanxp123 (talk • contribs) 04:09, April 23, 2011 (UTC)