Along with that, it makes each nonland permanent you control every colour and allows all of your lands to be every basic land type - which is a huge boon for a lot of five-colour decks
Just make sure you find a way to play lands off the top of your library as well, or youll find yourself stonewalled by basic Island more times than I care to admit
A large portion of the game comes down to figuring out how to balance mana production against casting spells
Most importantly, though, it serves as a marketplace for the cards they own
Overall, I think Amethyst got a lot of solid cards this set, but maybe not any standouts
Arclight Phoenix Aurelia, Exemplar of Justice Chance for Glory Divine Visitation Doom Whisperer Dream Eater Impervious Greatwurm Lazav, the Multifarious March of the Multitudes Mnemonic Betrayal Nullhide Ferox Ral, Caller of Storms Ral, Izzet Viceroy Thousand-Year Storm Trostani Discordant Underrealm Lich Vraska, Golgari Queen Vraska, Regal Gorgon