Bro it is easy... just farm normal duelist until you get one of the 2 farm skills Marik has... ( Balance, Draw sence low level ). If you get one of those 2 from normal duelists you can farm easily with the cerberus Deck. Farm REX (couse rex is for farming skills) like he did and you will get the skill... EASY(think for your self bro :P).(note: he has only balance and draw low for farm skills)
He told u the farming deck recipe now just focus on ur 🔥ing farm. Skill drop is totally based on ur luck and nothing to do with how many times needed to duel with the LD. I got my drop skills duel standby and three star demotion only in a day but took me 4 months to get the harpie hunting ground.
Anoymous
Zane
