one piece op10 most expensive cards The 10 Everybody Wants from TCG's Royal Blood (OP-10) The Most Expensive Cards In

This makes it one of the best cards for any Colorless deck (my personal favorite is Kozilek, the Great Distortion), essentially doubling all your mana

When you have more than 5-7 decks, you end up with decks that you might not love

Protect Your Passion with Precision

Scion of the Wild has power and toughness based on your total creature count, while Horn of Valhalla gives its equipped creature a similar stat buff

Even more crucially, it doubles on-board effects caused by your lands

I wanted to somehow equate this to a number of rounds in a tournament, but there is such a huge variation between formats (and even between decks) that I gave up