It's been a few years since Mantis Rider was a Standard staple and Kevin Jones won every Magic tournament he played in, and despite the card's obvious power level and favorable color combination, it hasn't found a home in Modern. Unfortunately, the card matches up very poorly against Lightning Bolt.
I know what you're thinking. Mantis Rider still dies to Fatal Push with a fetchland, so why should the dynamic change? In a slower deck, it wouldn't, but adding another qualifier to their removal means Mantis Rider is more likely to go unscathed, if even for a turn. That one turn only nets you three damage, so you need to put Mantis Rider in decks where that three damage is significant.
That means playing Lightning Bolt and Lightning Helix for extra reach, and of course we want Snapcaster Mage to go along with them. Path to Exile comes along for the ride because it's so good in Modern right now, and having all that removal means there is less space for counterspells, which is fine because this deck will be tapping out more often in the early-game anyway.
Mantis Rider's older cousin and former Extended standout Lightning Angel shows up because doubling up on the flying haste creatures sounds good. I'm not sure if you want to go bigger with something like Stormbreath Dragon or Thundermaw Hellkite, but those are definitely cards to consider in the context of your expected metagames.
Spell Queller is a bit out of place in such an aggressive deck, but it's just so powerful in Modern that I can understand its inclusion, although I'd strongly consider Geist of Saint Traft in its spot. Even as a four-damage burn spell that forces your opponent to leave back a blocker, it would be effective here and if you get a clear attack with it they will be in burn range immediately.
And finally, Steppe Lynx. It's great on turn 1 and pretty bad past that, but it's a one-drop, so that's kind of what you're getting into, and it is great on turn 1, easily getting in four or eight damage without an immediate answer. For all the removal and disruption this deck has, it's the presence of Steppe Lynx that lets me know it's an aggro deck at its core.
Jeskai Control has experienced a resurgence in Modern recently, and the wide range of builds around makes me think that it's due mainly to the quality of Jeskai's core cards in the current metagame. If Mantis Rider proves well-positioned as well, this aggressive list could be the best of them all.