Paying three black to draw 7 and then an additional black to get those 7 cards will cost a lot of life, but it seems like in most scenarios you will get pretty insurmountable card advantage out of that, and 7 life will be worth it
Arena of the Ancients does shut down legendary creatures, but the effect is symmetrical, so unless you specifically craft a deck that avoids them, it's going to impact you too
Like Gold Star Espeon, players who wanted to get their hands on Umbreon Gold Star needed to subscribe to the Daisuke Club and gather a staggering 70,000 EXP points during the 2005-2006 tournament season
However, Eevee also deserves some time in the spotlight without living in the shadow of its evolved forms
If you sacrifice a creature that is all five colors, you won't be able to find any creatures because there are no creature cards in Magic with six colors