yugioh legacy of the duelist link evolution superheavy samurai deck Core – Aus Ygo Superheavy Samurai Ogre Shutendoji |

R Rare Masked HERO Vapor X WATER Level 6 [ WarriorFusionEffect ] ATK 2400 DEF 2000 Must be Special Summoned with "Mask Change"

A lot of balance and care goes into choosing the cost of a card, more than I can express here, but looking for similar effects on existing Magic cards can give you an idea of a fair costfor example, a ramp spell that puts two lands into play ought to cost 4 mana, per Explosive Vegetation

While there are non-Flip monsters that have effects that activate when they are flipped face-up, these are not Flip effects

Cannot attack unless you control another "D/D" monster

There's water splashing all over the place, disrupted due to the presence of Urshifu VMax