Dark Mage & Sorcerer/Dark Knight
The Dark Mage class line in Fire Emblem Fates: Conquest offers a potent offensive magic-user, specializing in dark magic. These units excel at dealing high damage from a distance, often with the added benefit of debuffing enemies. The base Dark Mage class wields tomes and possesses decent Resistance, making them effective against mages and dragons. Their personal skill, "Morbid", grants them +4 damage when attacking an enemy with less than half HP, a powerful synergy for finishing off weakened foes.
Upon promotion, Dark Mages can become either a Sorcerer or a Dark Knight. The Sorcerer path further enhances their magical prowess, granting access to powerful spells like "Nosferatu", which heals the user for a portion of the damage dealt. Sorcerers also gain the skill "Tomefaire", increasing their magic damage by 5. This makes them formidable damage dealers capable of sustained combat. The Dark Knight, on the other hand, offers a hybrid approach, allowing the unit to wield both tomes and swords. This grants them greater flexibility in combat and access to the skill "Lifetaker", which heals them for 50% of their HP upon defeating an enemy. This can be incredibly useful for survivability, especially in challenging maps like Chapter 15, "The Dragon's Gate," where sustained combat is often necessary.
When considering units that can reclass into Dark Mage, Silas, a Cavalier, can achieve this through a Second Seal. While not a natural magic user, Silas can benefit from the debuffing capabilities of dark magic, especially if he has a good Magic growth rate. However, it's generally more effective to invest in units with naturally high Magic, such as Nyx, who starts as a Dark Mage and has exceptional magic stats. Be mindful of their lower Defense; they are vulnerable to physical attacks, so positioning them behind sturdy units like Knights or Paladins is crucial. Their effectiveness against armored units like the Knights found in Chapter 10, "Northern Exploration," is significant due to the elemental weakness of armor to magic.