Echoes of Eternity Echoes of Eternity is hefty at a mana value of six
URs have stronger floor value than SAR though a sets UR lineup rarely depreciates more than 20% even years after release, while a trend-driven SAR can move 4050% either way
In Constructed formats, if you want to use Attractions, your Attraction deck must contain at least ten Attraction cards and it must be "singleton"that is, it can contain no more than one card with any specific name (even if two Attractions of the same name have different text or lights)
Then again, some sets have headliner cards that are officially printed in a limited capacity but without a serial number, like the Infinity Stones, so the rules are fairly inconsistent
you can't spend them on your costs
Most of the time, just straight killing them is enough, but there are some peculiar scenarios when you can't kill the creature and it's probably best to keep them bound to the earth to prevent them from posing a major threat