People still play herald? Also I was thinking shikana + ferocity. Herald is just way too predictable and I feel like its easy to stop with other methods if you see it coming.
Only in 3 FD, because it lacks any burst damage.
Herald does have some advantages over ferocity, it lets you Shikana on turn 6. While it is predictable, a lot of decks still can't do anything about it. You can also use Herald to bluff Shikana, which normally buys you a turn. Herald on turn 8 for example is very threatening, because on turn 9 you could either Shikana or ramp to Calamity.