The more important note is the idea of a shared theme: being themed around a permanent type mostly
Invasion of Tarkir / Defiant Thundermaw Tarkirs Invasion, aptly named Invasion of Tarkir, comes in at just two mana and deals at least two damage to any other target
Cloud Strife, from Final Fantasy, became Najeela, the Blade-Blossom, since they're both powerful sword fighters
Added some incredibly powerful cards that improved existing decks/archetypes
Most Popular Explorer Preconstructed Deck, Bo1: Azorius Control This is a lot less clear because: There's scarce reliable data for Explorer Bo1, and We're entering uncharted waters: there's no way of knowing how Pioneer Masters will impact Bo1, since there's no paper counterpart to compare