The main thing is to have as much removal as you can carry, and dont be too hasty trying to force a win save the kill spells for big threats or when you know it creates a lethal attack
Copies in better condition and scarcer finishes generally sell for more
It can provide a much-needed boost or some padding to your life total that lets you make riskier plays later on, on top of denying your opponent a spell
These are explained as fragments of a larger story, and are kept in the Great Illuminary
This is a stark contrast to, well, pretty much any other commander out there, which will often be sent back to the command zone and require you to waste turns tapping out to recast them
It's also one of the best enchantments to reanimate with Anikthea, Hand of Erebos, since it'll be a token creature that can copy itself