A good creature for the deck is Obsidian Charmaw a 3RR dragon that costs 1 mana less to cast for each colorless producing land an opponent controls, when the dragon EtBs it blows up a non-basic land. It has a strong EtB effect, is a dragon, and very likely has a higher cmc than the cost you pay to cast it.
Something to keep in mind playing this deck is that Emerge only reduces the cost by generic mana, so any colored pips in the emerge cost must still be paid For example if you Sacrifice a 9 mana Skitterbeam to Emerge Herigast you still need to pay RR, it doesn’t make Herigast free to cast
An artifact that I think is a must is Cauldron of Souls. Getting the sacrificed creature back and getting another etb is so good, it works well in my Purphoros Bronze Blooded deck. If you have Zealous Conscripts I would put in Kiki-Jiki, Mirror Breaker, Kiki has good synergizes with most cards in this desk but with Zealous Conscripts its a combo that forces opponents to answer it or the game is over.
Having played against this deck - it is pain. It popped off so quick and overwhelmed the board. The cards it stole from me allowed it to steamroll even more.
I have this deck too, Skitterbeam the GOAT, however I think it runs smoother if you invest heavier into colorless critters, rather than dragons, since you can't reduce colorless costs as others have mentioned. for some tech, Molten Monstrosity is a good option, being an 8c creature that usually costs a single red. Another fun bit of tech is Phial of Galadriel, since it'll up the card draw on Herighast's ability, from draw 3 to 4, which is nice incidental value on a card that has a baseline of being a 3cmc rock. Relic of Legends is also pretty wild, since you'll often cycle Herighast and other legends in and out of play.
This deck looks dope! I think imma convert my Jaxis EDH deck into a modular EDH deck. That way I can run either Jaxis or switch to Herigast as the main commander.
Summoners egg and clone shell are great ways to make you the archenemy turn 5. I run a more artifact based deck, as dragons feel like committing too hard to valuetown
