there's only two ways of using player input (during game play) via the command~text box at the bottom of screen:
.1. the 'get input' Script:
(Elements: GUI~Editors' Verbs ~ Object's Script Attributes, Functions, Commands, Turnscripts, Timers, etc) -> run as~a script -> ouput -> 'get input' Script
http://docs.textadventures.co.uk/quest/elements/
.2. the 'Command' Element ( http://docs.textadventures.co.uk/quest/elements/command.html )
right click on the specific room(s) that you want where the 'attack' occurs (this should also have the Timer~Turnscript added to them too) and select 'add Command'. This is known as 'local' usage, as they're tied to specific rooms, and not the entire game.
otherwise, if you want global Turnscripts~Timers~Commands, right click on the upper-left-most 'Objects' in the left side's 'tree of stuff, and 'add Timer~Turnscript~Command' to make them global (applying to the entire game, anywhere in the entire game, and not just only to specific rooms).
hopefully it is pretty self explanatory....
the 'pattern' text box, is what is required for the person playing the game to type in, to activate the Command. So here you can put in your 'x' (you'll have to type in the x in the command~text line box during actual game play, but that's pretty much the same as pressing the 'x' keyboard key, lol)*
*Jay (Jaynabonne) may know of a how to directly 'hook' the pressing of the 'x' key, if it is possible. So you can try asking him if its possible, and if it is, he can likely help you with it.
the 'scripts' adding is what will be a bit complex... due to the designs you mentioned.
if you're using a Timer or Turnscript for your 'attacks upon you', then the script for the Command would just be the 'disable Turnscript~Timer' Script.
however, if you want the 3 attacks design, that's going to take some more work, as you got to do the scripting and Attribute adding that is needed for it, both within your Turnscript~Timer and your Command.
try looking at this thread, as it's design method is similiar to what you need~want to do:
http://ifanswers.com/896/quest-having-trouble-with-turn-scripts
or the original source (though this is a bit different design wanted, but it's what used as the basis for the above link):
http://forum.textadventures.co.uk/viewtopic.php?f=10&t=5347#p37066
so, this link may confuse you worse.