In Helix you'd have to x downward or use v to enter visual mode. But you initially said that you "found kakoune bindings limiting". In kakoune you can 8Kxd, or 8K<a-x>d on less recent versions. The vim approach is usually superior for simple commands like "delete N lines", the kakoune approach is superior when you want to compose commands, e.g. `%sif<ret>f(<a-i>(sand<ret>cor` is "select all `if`, find `(`, select inside `(`, select all `and`, change to `or`"