The vast majority of non-black tutors tend to come with some inherent drawbacks due to the ability being primarily under black's jurisdiction
Up until this set, only one and two coloured token cards existed
Legality depends on the tournament format -- Earth Kingdom Protectors can be legal in some formats and banned or restricted in others
Oracle gets away with not only being a 4 drop ramp effect but also a weak Exploration because she is self contained and a source of ongoing card advantage
To its credit, Wizards own client is very, very generous with its starter decks, which makes it an easy recommendation to anyone new to Magic, especially when paired with a solid tutorial
Playing a full complement of Madame Medusa - The Boss is also a clear nod to the Castle plan, because you do not care about her low Lore value compared to other options like last season's staple, Lady Tremaine - Imperious Queen