The Salvatore brothers might be a bit protective at first. Damon would probably be skeptical about Kol being in the picture, but over time he'd warm up to the idea for Elena's sake. Stefan would be more accepting right away and offer his support. Bonnie would be excited and use her magic to make sure the baby is safe. Caroline would be all over helping with baby clothes and advice. As for the Mikaelson family, Klaus might see the baby as a way to strengthen his family's hold in the supernatural world, but also be protective in his own way.
Caroline would probably be very shocked at first. She might have some concerns about Kol's intentions, but seeing how much he loves Elena and how excited they are about the baby, she would gradually come around. Stefan would be more reserved in his reaction. He would be worried about Elena getting hurt, but he would also respect her decision. Damon, on the other hand, would be more vocal. He might make some snide remarks at first, but deep down he would also want Elena to be happy. Bonnie would be practical. She would offer to use her magic to make sure Elena has a safe pregnancy and that the baby is healthy.
Their friends might be shocked at first. Damon, for example, might be a bit jealous as he had feelings for Elena in the past. But he would also probably be protective. Bonnie would likely use her magic to ensure the pregnancy goes smoothly and help protect Elena from any supernatural threats. Stefan would be supportive, seeing it as a new chapter in Elena's life.
One possible storyline could be that Kol and Elena's relationship starts in a rather unexpected way. Maybe they are forced to work together to defeat a common enemy in the supernatural world. During this time, they gradually develop feelings for each other. And when they find out Elena is pregnant, they face a lot of challenges. Some vampires might oppose their union because of Kol's past actions. But they decide to fight for their family and the future of their baby.
One idea could be that the baby has special powers due to Kol and Elena's unique heritages. For example, it might be able to control both vampire and witch magic in a new way. Another plot could involve the baby being a target by various supernatural forces who either want to use its power or destroy it out of fear. And perhaps the baby's existence could bring about a new era of peace or chaos in the supernatural world, depending on how it's raised and the choices it makes as it grows up.
Sakura would be overjoyed. She's been Naruto's friend for a long time, and she would be excited to see him start a family. She might offer to be the baby's doctor and make sure the baby is healthy. Shikamaru would probably be a bit lazy about it at first but would come around and offer his strategic mind to help protect the baby if needed.
Caroline would probably be overjoyed and very helpful. She might offer to babysit all the time and give parenting advice based on her own experiences or what she's read. Damon, on the other hand, might be a bit more cynical at first, but eventually grow to love the baby and become very protective.
Stefan might be initially shocked but then be very supportive. He would probably offer to help in any way he can, like babysitting or giving advice based on his own experiences. Bonnie would be excited and use her magic to create some special things for the baby, like a protective charm.
Grover would probably be really excited. He might bring all kinds of nature - related gifts for the baby, like a special plant that has protective powers. He would also be very protective of the baby, using his nature senses to detect any danger.
Their pirate friends would probably be both excited and a bit clueless. Jack Sparrow might try to give the baby some 'unique' gifts like a small piece of treasure or a strange trinket. Gibbs would offer practical advice on how to keep the baby safe on a ship if they ever take it to sea.
Chad would be a very protective and gentle presence. He would be like an uncle to the baby, always ready to pick the baby up and play with it. His calm and strong nature would make the baby feel safe.