ViEmu commands

If you use Ctrl-V or Ctrl-Q to enter visual block mode, and select a range, you can key in any operator directly and it will be applied to the range. Here are some samples:

d Deletes the block (and copies it to the default register for later pasting)
y Yanks the block (copies to the default register)
gU Makes all characters uppercase
gu Makes all characters lowercase
~ Toggles the case of all characters
c Change - deletes the region, enters insert mode, and then repeats the string input in all lines (if we were initially in block visual mode)
etc...

The docs have a complete list of ViEmu-supported operators.

'x' also works to delete a visual region.