There are only about 8 to 10 of this card in existence as it was printed with an error of having a large green 'PRERELEASE' stamp right next to Raichu's cute little foot
Tasha, the Witch Queen Theres a staggering divide between how popular and how good Tasha, the Witch Queen is
A good rule of thumb is to run 35-38 lands with a handful of mana rocks or other sources of ramp, probably about eight
MTGA Codes, a retail website that collects unwanted and unused Arena codes and sells them directly online, regularly runs such giveaways to drive engagement on its Twitter account (@MTGA_CODES)
The decks would play differently just based on how they interact with the commander, but I don't know how different the base of each deck would be (compared to, say, Gisa and Geralf, which is much more of a milling focus)
WOTC continues to focus on reprinting to improve barriers of entry for Modern and, to a lesser extent, Legacy