Each one has a strong questing value that forces opponents to challenge or risk falling behind, and then once challenged and/or banished, their effects activate drawing you cards, forcing opponents to discard or return a character to their hand, and more
The first one, Princess Power is a well rounded Amber-Sapphire deck filled with Princess Characters and cards that interact with them
You want to load your deck with expensive cards to increase the odds of winning clashesthough you dont want cards that cost more than 8
Faced with fierce competition, bombarded by stardom, and confronting dangerous schemes brewing around her, Chandra is determined to race for Nissa's future
They don't want to cast stuff that will be destroyed in a turn or two, so they hold back
A 5/5 with wither for seven mana seems like a bad trade until you take that untap ability into account