Welcome to Magarena, dragonryu

Currently we do not support choosing a creature type, hence
Door of Destinies cannot be implemented
Do consider a different card, perhaps a card that is similar to cards already in the game. You can find ready made card scripts in the Magarena/scripts_missing folder for all missing cards, some may already work as it (just need to move it into the scripts folder), some others will need groovy script, and the rest are not implementable currently.
https://code.google.com/p/magarena/wiki/UpcomingCards is a constantly updated page showing the cards that will be available in the next release, 1.52.