You can cast spells from your hand without paying their cost for as long as this card remains on the field
The Court of Garenbrig makes you the monarch when it comes into play, and then at the start of your next upkeep, you get to dole out two +1/+1 counters across up to two creatures
So, even if Sephiroth gets removed at this point and never sticks around long-term, the damage is done
Plaguecrafter's Familiar is fairly high in our rankings for one reason: we've already seen that giving Goblin Chainwhirler deathtouch can be somewhere between good and game ending in the right matchup, and Plaguecrafter's Familiar offers an on-curve way to give Goblin Chainwhirler deathtouch while it is still in your hand, so you don't need to go through the janky process of playing it, needing it to die, and then trying to reanimate it with Call of the Death-Dweller
The community usually prefers black-bordered cards both because of the visual appeal and the fact that they dont show dirt or wear nearly as easily as white-bordered cards
