30th - big purple sabaiman
50th - 3 headed bettle
?th - blue robot, never fought him, probabbly 40 or 45
15th - Big evil minotaur
25th - grenn buyon
35th - awesome ant - like blue boss
You can use white stones till +15 but you will still playing cards
you still can get fail or broken but with fail your stone only breaks and when you get broken it downgrades -3 with pure and -1 with normal stones