One of the many gameplay modes in Fire Emblem Heroes is Arena Duels. This is the game’s PvP mode, allowing you to square off against a pre-selected team from another actual player that’s controlled by AI.
Participating in Arena Duels will net you points that compile over a week-long “season” in the arena. At the end of the season, you’re ranked depending on the points you have earned in battle. You can gain bonus “Chain” points for logging 7 consecutive victories.
Unfortunately, to participate in Arena Duels, you’ll need Dueling Swords. These are essentially a form of currency, limiting how many times you can duel in a day. Each battle will consume one Duel Sword.
So how do you restore more Dueling Swords? Unfortunately, there are only two ways to restore these, and neither is a really good option.
The first (free) option is to simply wait. All three swords will replensih every day at 12:00am (midnight). This essentially means that if you don’t pay money, you can only duel three times a day. Kind of lame.
A quicker, albeit pricier option, is to use a Dueling Crest. Consuming a Dueling Crest will instantly restore all three Dueling Swords. Unfortunately, Dueling Crests will cost you. These can be purchased with real money or redeemed with 100 Platinum Points through My Nintendo Rewards.