All around I think the deck holds enough value to more than make up for its cost
He's since been killed (again) and replaced by Vraska, who now is also missing in action
And thats not even factoring in his enters-the-battlefield trigger, which essentially goads every opposing creature in play, creating political chaos and the potential for more life drain triggers as well
Emotions aside, Hissing Quagmire seems like a lot of the dual lands that enter the battlefield tapped
The power of Umezawa's Jitte is that it destroys creature decks, and while it might be a bit slow for Modern, it would still push certain decks (like Elves and perhaps even some Collected Company builds) out of the format
There you have it, my Top 20 Standard Cards from Amonkhet