In that artwork Stuffy is is bound and has been painted with purple, aqua and white paint for Leshracs Rite
The only downside for Zareth is if you want to use its second ability, you have to somehow get it into your hand, which can be done with ninjutsu cards like Prosperous Thief, trading them back and forth from your hand
Having to hold mana up is potentially more annoying than being a free activation, but you do end up getting both hexproof and indestructible, making it worth the mana
Even without intending to, you'll quickly work out which cards aren't pulling their weight, and start seeking replacements
Its even a strong disruptive piece at higher-powered tables where 0-mana artifacts and free spells like Force of Will abound
#9: Soulless Jailer One of the hallmarks of the Modern form is very powerful, fast decks looking to execute a very specific game plan, which makes hate cards incredibly important to the format