|Marth plays a versatile role for his team. He can support his team by buffing their stats, slay troublesome dragons that the player faces, and either keep his teammates healthy, or he can further improve his own combat prowess.
Weapon: Falchion (Mystery) is Marth's weapon of choice, and it boasts a few effects. When given its special skill, any ally standing near him will be buffed for +2 to all stats, which can give them the upper hand in combat, or it can help them withstand more hits. Marth can also then augment those buffs further with the right skills, making him a great team player. The Falchion will also grant Marth some recovery every other turn, improving his sustain, offsetting the self injury from Fury 3, and it can help him perform a healing role if need be when used with Reciprocal Aid. Finally, it's also effective against dragons, which will let Marth be his team's answer to any opposing dragons.
Assist: Reciprocal Aid allows Marth to act as a healer of sorts, and is best used if he has Renewal 3 as well. With these skills, Marth should heal 20 HP every other turn, as well as 20 HP at the start of each map for endurance styled modes. He can then proceed to share his pool of HP with injured allies and have his skills heal back up the damages for himself. Should the player use Marth in other modes or feel like this is not necessary, then another Assist like Reposition can be used instead for its movement utility, helping Marth move his allies around instead.
Special: Glimmer is Marth's Special. With its fast charge, Marth will be able to rely on it to add more damage to his attack, which should help give him the upper hand in battle and secure victory against his opponents.
A Passive: Fury 3 is chosen as Marth's A skill. It boosts his overall combat performance by bolstering all of his stats at the cost of 6 HP after each engagement. With the Falchion's self recovery however, this draw back becomes minimal, although he should still take caution in endurance styled modes. Alternatively, while a more elusive option, Marth can use Distant Counter to ensure that he's not helpless against mages and some archers.
B Passive: Renewal 3 is an option for Marth's B skill should he decide to go the healer route, and is necessary when he has Reciprocal Aid as his Assist for this purpose. This is what will help Marth heal even more HP throughout the map, and it lines up perfectly with his Falchion's effect, allowing him to heal 20 HP every other turn. Should the player feel like this extra healing is unnecessary, then he could use other B skills that can help him defeat his opponents better. Swordbreaker 3 would be a good option in that case, allowing him to duel opposing sword wielders and come out on top.
C Passive: Drive Spd 2 is suggested as Marth's C skill as it works well with his Falchion's stat buffing ability, as both affect allies within two spaces. Any ally within two spaces of him, with just this skill and his weapon's effect alone, will be granted +5 Spd during combat. Should Marth want to be a more defensive buffer, he could also opt for Drive Def 2 or Drive Res 2 here instead.
Sacred Seal: Drive Atk 2 is suggested as Marth's Seal as it also works well with his Falchion's stat buffing ability, as both affect allies within two spaces. With it and Drive Spd 2 as his C skill, any ally within two spaces of him is granted an impressive +5 Atk and Spd during combat, as well as +2 Def and Res for extra bulk. Marth can also opt to be a more defensive buffer with Drive Def 2 is as his Seal instead, which can then stack with another Drive Def 2 in the C slot, or he could use Drive Res 2 in the C slot for a more even defensive buff. Marth can put any combination of these Drives to fantastic use, and the player can mix and match at their own discretion to fit what is needed most.