Accelerate some Energy to it with Magma Basin [Brilliant Stars], and hit for a whopping 160 damage for a single Energy
To this point, Greninja ex has not seen much play as its own dedicated strategy, but it does see play as an alternate attacker in Palkia VStar/Dusknoir lists
You'll want a deck and a commander that can put counters to good use (luckily, Tidus, Yuna's Guardian brings a whole Commander precon with exactly that theme!), and a board ready to roll with the dice
The final value of this Secret Lair is undoubtedly going to be much higher, but since theyre based on basic lands its hard to say exactly what itll be worth
Scapeshift can be a great way to get a lot of landfall triggers in a single turn and can trigger other abilities focused on lands leaving the battlefield
At minimum, it functions just like your average three-mana rock