atm the said wk+kk card combo only affects medium size mobs. as clearly stated on the cards descriptions the combo should affect large mobs as well.
the attached screenshots shows the bonus it gives thru the command @battlestats (screen shots with and without the combo card)
to further support this bug report i tested the damage on a large size monster with and without the combo. ( as screen shot shows no 15% damage bonus and 5% redux bonus received even with the cards equipped together)
tested the damage on anubis http://ratemyserver.net/re_mob_db.php?mob_id=1098&small=1&back=1
as one of the common generic cards this needs a fix please.
thanks as always