When you touch someone they start to have lines all over their body (Just like the lines when Sakura Haruno uses hundred healings, Sorry that was the only example I could figure out to show you what I mean) and then the lines start to glow (f/c) and the person disnitegrates into little sparkles that then come together and form into a black rose.
𝐋𝐢𝐠𝐡𝐭𝐧𝐢𝐧𝐠 𝐝𝐞𝐚𝐭𝐡:
When you active lightning death you can lift some of your hair strings and make them longer and you can also rap people around with your hair strings. Kinda like what Ibara Shiozaka the girl from class 1b did to Denki in the sports festival (If you watched my hero academia you know what I mean) but expect you don't lift your whole entire hair up only some good amount of your hair but you can if you want to but it's straight and sometimes when it's you have it all lifted up it's like floated. Y'know how Daki uses that sash of hers? Yeah the same thing with the reader but it's her hair not a sash😭 (If you watched demon slayer you know what I'm talking about) And so when you lift your hair up and rap people around it, you can also zap them with lightning. And then you can turn your hair back to it's normal form. Wanna know why the ablitiy is called 'death' lightning. It's because you also have this other form where appears a skull tattoo on your forehead and you have skull pupils. And (f/c) strings in your hair. (f/c stands for favorite color) The reason is because the skulls you have in your eyes in your pupils, are what you call 'Death eyes' The reason you calls them that is because when you activate them, let's say you look at some people and then you unactivate the death eyes. And in just a second you'll see the people who you looked at with your death eyes literally dead on the ground and their head is not connected with their body like their head has literally fallen off their neck. And then you can see them all dead in the ground with their heads unattached to their necks and their all dead and around you.