This deck is designed with newer players in mind, and is part of a series of decks that can be contructed using cards from only the Revised Core Set and one other purchase: Riders of Rohan.
This deck has a relatively low cost-curve, with most cards only costing 1 resource, none of them costing over 3. It uses Horn of the Mark as a way to consistently draw cards, with Ancient Mathom providing bursts of additional cards.
Lothíriel will be your primary quester, bringing in an additional ally as well every quest phase. This ally will leave play, giving a boost to Éomerr, who will be your primary attacker, while Fastred will cover your defense and threat management both at the same time. This deck will quest pretty strongly with allies like West Road Traveller, Westfold Lancer and Éomund each contributing 2 , while The Riddermark's Finest and Westfold Horse-breaker both provide 1 for only 2 cost. Should you require it, Astonishing Speed will give you a hefty bonus of 2 for each and every Rohan character committed to the quest. If you combine this with Lothiriel’s ability to bring in Eomund for the quest phase, only to have him return into your deck, then all of your Rohan characters will ready immediately following the quest phase and you will be all set up for the combat phase.
Fastred will be your primary defender, bolstered by Unexpected Courage, Blade Mastery and Hasty Stroke. Anything more threatening than that will need to be either Feinted, blocked by an expendable ally, or Eomer with Firefoot would need to preempt them with a Quick Strike for an attack of either 5 or 7 . When it comes to attacking enemies, especially if the Westfold Lancer can soften them up first, you might be able to spread the damage round from Eomer using Firefoot’s effect to a second enemy, which he could then finish off after using Rohan Warhorse. Westfold Lancer and Riddermark Knight can both chip in for attacks with 2 each, but Westfold Outrider can provide some potential beyond its attacking strength. Discard it for its ability to engage an enemy during the combat stage, after the enemies have made their attacks. This will open it up to an attack from Eomer without the need for defending against it first or using a Feint on them.
For more decks that can be built with only the Revised Core Set and one additional purchase, check out this article on Vision of the Palantir here: https://visionofthepalantir.com/2023/01/13/ten-decks-for-new-players/