you can do it using events, giving moving options so on, using move events.
not allowing to choose spots that another tool event of your side is in (by conditional branches) and make a conditional branch of if opponent event is on a square you walk on then opponent event is erased.
the main problems are:
defining king's lock (checkmate)
but possible i think
making the "computer" act like he knows the game
the easy solution is to randomize his moves and try to move the king when another tool got aim on it, but that will make him easy and i doubt he can really save himself under that condition for more than 1-2 turns
basicly for the a.i you need loads of hours and you need to be a good chess player seeing as only a good chess player can tell you what's best to do in what situation ,and then you need to condition every move possible
in total..
hours over hours of work, no matter if you use events or a script since each case have to be setted on it's own.
(so that's hours of work.. as for tool moving.. that's easy.. give the player his legal options each time... need to move 2 up 1 right or 2 up and then 1 left , give him 3 options like:
move to F5
move to F7
Choose another tool )