Hi! Played Secrets of Bloodbending earlier on Arena. I'm using a PC. I controlled an opponent for the default version of the card and they had a flash spell (Tishana's Trickbinder) and open mana, plus a fountainport that could have sac'ed a token. Secrets of Bloodbending says I control them during their combat. I should have been able to cast their spells during combat and use their lands, but that wasn't allowed. It seemed like the card only allowed for me to choose attackers as opposed to fully control them.