Lightsworn have never had Extra Deck monsters before, but that all changes with the all-new Synchro Monster, Michael, the Arch-Lightsworn , capable of banishing any enemy card while refilling your Deck and your Life Points
The rest of the cycle from Eventide are equally enigmatic, like Overbeing of Myth (those are owls on the shoulders and head of a humanoid with a blindfolded face), Nobilis of War (yes, its a goat chariot), Deity of Scars (your standard minotaur-esque fella) and Dominus of Fealty (a flying Eldar wizard made of clouds)
If it's there, you have a First Edition
They're not the type of cards that you build deck lists around, and as I mentioned in the intro, they are cards that both players and Wizards hope don't end up in deck lists
Since Marath gets more +1/+1 counters every time you recast it, synergies with cards like Hardened Scales or Cathars' Crusade can quickly snowball