The thing that elevates all this is the existence of a card like Curious Obsession
When it comes to creatures, spells, and land, Wizards has years of experience and data to figure out what the right baseline power level is, and as we just talked about, they tend to aim far enough to the "safe" side that even if they miss, the result is a very good card (like Collected Company), rather than a ban-worthy monster
Legality depends on the tournament format -- Kassandra, Eagle Bearer Card can be legal in some formats and banned or restricted in others
Commander is one of the most popular formats in Magic
Yuna, Hope of Spira Gameplay The centerpiece of the Naya Yuna enchantment deck, this FINAL FANTASY hero creates an incredibly resilient board