Forum:To attack.... or not to attack

I'm confused...... can anyone help me assess this situation.....

Player A, the turn player, with Mobius, attacks Player B's monster, Ninja Grandmaster Sasuke. Player B activates a trap card which is Ninjutsu Art of Transformation, special summoning Mystical Knight Jackal from the deck to the field.

Will this be a replay or will it continue to damage step?????

Pls. help.....