Often, themes of self - discovery are present. As they interact, they might learn more about themselves. Also, themes of loyalty, as they support each other through different situations. The contrast between their different universes can also lead to themes of adaptation and understanding.
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Robin would probably be both scared and angry. He's a brave kid, but facing the Joker alone is no small feat. He might initially try to fight back if he has the chance.
Robin would probably be very hurt. He might initially go into a state of shock and disbelief. After that, he could try to find evidence to prove his innocence. For instance, he might search for surveillance footage or eyewitnesses.
Robin would probably stay calm and observant. He's been trained well, so he'd immediately start looking for any weaknesses in his captivity situation. He might try to pick the locks on his restraints if he's bound, or find a way to communicate with his team secretly if there's a chance.
Robin might initially be defiant. He's a trained fighter and detective, so he'd likely try to gather as much information as he can about his surroundings. He could be looking for any weaknesses in Lex Luthor's security setup or trying to figure out what Luthor's endgame is.
Batman would likely be extremely angry and determined. He'd immediately start using all his detective skills and resources to find Ra's al Ghul's lair. He might also call on his other allies in the Justice League for help, as Ra's al Ghul is a formidable foe.
Their friends would probably be very excited. They might bring gifts for the baby, like special toys or clothes. For example, Starfire could bring some alien - made baby clothes that have unique properties. Cyborg might build a high - tech baby crib with all sorts of safety features and fun gadgets for the baby to play with.
Their friends would probably be very shocked at first. For example, Starfire might be a bit confused as she has her own unique view on relationships. Cyborg could be initially taken aback but then might be supportive once he sees that Beast Boy and Robin are happy. Raven, on the other hand, might be more reserved in her reaction, but deep down she might be glad that they've found something special with each other.
Batman would be heartbroken. He has trained Robin and sees him as a partner and almost like a son. He would first try to talk to Robin, to find out what made him turn evil. He would hope that he could reason with Robin and bring him back to the good side.