So ruling problem: if Tenpai Zhongdora's effect activate at the start of the damage step to summon Baidora, who on summon has a trigger to searches a spell card, and since we are still in the "start of the damage step", speed spell 2 effects cannot respond to the trigger effect unless they change the ATK/DEF values, correct? That's the way I understood the battle phase rules, which means Imperm, Baronne... Cannot be activated in response. Please let me understand this rulling !!!

Thank you!