Does Juragedo always cause a replay?
No Juragedo does not always cause a replay. A replay only occurs if the number of monsters on the field changes while an attack is being declared, but before the damage step. Therefore Juragedo can cause a replay, but does not always cause one. If Juragedo is summoned as soon as the Battle Phase starts, then a replay will not occur, but if it is summoned immediately after an attack, then a replay will occur.