The effect of this card treating battle damage as effect damage is very unique, but not useful in current card pool due to its low stats.
One of the most used cards in farming LDs when used with Union Attack.
Easily unlockable and accessible.
Very low stats.
As mentioned above, it can be used with Union Attack to farm LDs. It can direct attack with Secret Pass to the Treasures. Thanks to its low ATK, Secret Pass to the Treasures can be used on Gravekeeper's Vassal.
This card's interaction with angel 07 and union attack is broken. Union attack increases a monster's attack significantly but can deal no battle damage. If angel 07 prevents all effect monsters' effects, like how it prevents your spirit monsters from returning to your hand at end phase, it should also prevent vassal's effect of converting battle damage dealt to enemy LP into effect damage but no. If angel 07 is out on the field, you should not be able to trigger its effect and consequently not deal any damage to enemy's LP if you used union attack(s) on it.
here is deck its tested vs lvl 40 mai,Tea,every lvl 10,20Ld,few vegabond comatible challenges
Modify deck to fit need of opponet deck.
Youll need to draw cerberus at turn 2 after u take dmaage so use lp decrease spells like lithograph to lower lp if enemy couldn't.
Note : make a 30 Card deck since u have 3 shard and 1 cupof ace if you got.
Youll need draw ur deck before enemy get deck out so have atleast 4 drawing spell cards
I also got lucky vs yugi moto he too use cerberus in 5th turn so my cerberus was more stronger with union attack i was able to get 55K damage against lvl 40 yugi moto.Still u need 3 union in deck to achive around 50k damage. Grave keeper vassel let u inflict damage as it is not battle damage but effect damage.
Deck is already posted in comments
Lol this card let you do insane damage
Beware cerberus deck guys.....this little card talk damage