The Guildgate cycle is pretty cheap on the cost, and I doubt this will be too pricey, so this is a nice budget mass color maker there
Jaheria is honestly a busted little Magic card, and one that I feel could easily have been written as creature tokens you control
If a creature card was exiled this way, each opponent loses 2 life and you gain 2 life
Note that even though the last week of previews was cut short by the full set spoiler, the last Friday was still officially part of the last preview week, so it was still considered two (or in the case of Scars, three) weeks of official previews
That said, there is an audience that wants to see incentives to play the fewest colors in Commander and those kinds of answers are not going to be properly seen in a Standard-legal product
The addition of Red to the possibilities means that we can take advantage of cards like Devastating Summons, Feldon of the Third Path, Flameshadow Conjuring, and Godsire to create either massive creature tokens or copies of tokens that were meant to only last the turn, but can now stick around