I tribute summoned Maju Garzett. It had 3200 ATK. My opponent in a PVP duel used Riryoku, so it had 1600 ATK. It survived the attack since I activated Wall of Disruption. However, at the end of the turn, Maju Garzett's ATK and DEF were 0. Shouldn't they have gone back to 3200 ATK? Riryoku doesn't say it should return to original attack, just that the effects only last til the end of the turn, so I think it may be a bug?
It's probably because maju says " the ATK of this card becomes" and not the original ATK. Yes, after ririoku loses its effect Maju's atk becomes its original, witch is zero.