Yami Marik Unlock mission issue

[✪trololo]

Hi. I play the mobile version of the game.In order to unlock Marik the last mission I can't accomplish is the following:
Use level 10 or higher Monster Cards 1 time(s) in one Duel against Yami Marik at level 30 using Mai Valentine.

What I am trying is get or recover as much HP as possible and use Cyber-stein in order to pay 5000 hp and summon Blue-eyes Ultimate Dragon (level 12). I attacked with it, tributed etc. so I don't know why the mission didn't unlock. Any help would be appreciated.

[DUBINA]

you need to activate an effect of the lv10 or higher monster in order for it to count. like for example yubel 2nd or 3rd forms.

[✪trololo]

Originally posted by DUBINA:

you need to activate an effect of the lv10 or higher monster in order for it to count. like for example yubel 2nd or 3rd forms.

thank you. even the effect that you destroy a monster in order to keep yubel alive worked.