I've just realised there's actually no reason beyond llanowar elves why this has to be in historic, so after uploading I'm going to play around with this in standard.  I made this deck because nikya + cavalier of flame is an established, although not often played combo, and one of my favorite timmy plays. I've never seen a varient in Jund, nor with nyxbloom. Beyond CoF, Nikya and Fires, the card choices in this deck are entirely my own. So any feedback would be really appreciated.

How it works for those unfamiliar: Fires of Invention fixes your mana and can get the combo pieces (Nikya/nyx + CoF) both down on the next turn. Nikya's passive allows you to generate a lot of mana but only lets you cast creature spells. Luckily activation abilities are a great way to spend this mana. Casting a Cavalier of Flames to boost and haste your Nikya/Nyxbloom and stomp is the preferred way to win with this combo.

Beyond the base combo:

Nyxbloom adds some insurance in case you don't find a Nikya. If you have both down, I believe each land taps for 6. Nyxbloom having trample is also a nice addition, as after a few cavalier +1/0 boosts it can help close out the game.

Mana dorks: dorks can get the combo off potentially as early as turn 4.

Card draw: Nothing worse than a combo that goes unassembled. Stormfist, Beast Whisperer and Rankle all give us card draw while the latter can additionally provide some hastey sacrifice removal. Having a big hand can be great with CoF's ETB. Especially with Bucc on the board.

Glinthorn Cycle Synergy: Buccaneer is a little bit of an MVP. If you DON'T draw CoF, it's activation ability can be a nice payoff/use of mana. It  allows you to cycle for other combo pieces, while pinging for a lot of damage. And if you DO draw into CoF once buccaneer is down, CoF's ETB ends up doing damage. Lastly, if you've been cycling away your lands with Buccaneer, CoF's ETB or Rankle, CoF's death effect is also potentially a considerable chunk of damage to your opponent.

Not sure about Spawn of Mayhem. It's a powerful card and adds ping pressure. Flying and trample mean that it's a very nice target for CoF boosts. However, Massacre Girl might be a nice sub, as other than Rankle, we got no removal. Dreadhord butcher might also be fun in this deck. Its great pressure in the early game, and thanks to CoF's activation, lategame it can do a big chunk of damage when it dies.

All in all I think this deck assembles the combo pretty nicely thanks to the card draw, cycling, and the nyx/bucc alternatives to nikya/CoF. The large amount of incidental damage, combined with high preassure creatures can often win games outright without the combo.

Finally: just realised that Nikya's limitation to creature spells might synergize very nicely with Thalia. So I'm going to try and figure out a Naya version too.