Question about hidden units at a battlefield | tcgmode

When I conq. a battlefield (1.) and then place Tideturner Hidden (2.) And then move Irelia with a Spell on another BF (3.) : Question 1: Does Tideturner stay hidden when he is alone ? Then if yes, does he still stay hidden when I pass turn and my enemy tries to conq. the BF my Tideturner is on...