Since both
effects don't happen at the EXACT same time, you can reveal once, then reveal again.
Same for something like Tethys - You reveal the
fairy you drew for one Tethys, then chain by revealing it for a second Tethys, then chain again for a third Tethys.
;D
But discarding your Iron Core would only work for one of your Koa'ki Mieru
monsters at a time. ;[