(Opened May 11, 2015)
There are plenty of cards between Khans of Tarkir and Dragons of Tarkir that reference one another because both expansion sets are supposed to depict alternate timelines of the same world. Two of those cards are Herald of Anafenza (from Khans) and Herald of Dromoka (from Dragons), which are sibling cards not just by name, but also by art (as shown by the sounding horn that each herald is blowing).
I kind of wished, however, that both cards tied with each other mechanically as well. Could Herald of Anafenza have granted some other abilities to other Warriors as well? Could Herald of Dromoka somehow spitted out Warrior tokens, or had some Bolster action to mirror the other herald's Outlast ability? It's tempting to assume that both had either one time during design and just got changed for developmental reasons, but I suppose we'll never know: Tarkir as it existed during the times of the Khans no longer exists.