Aether

A special famous for being the signature move of Ike, Aether is one of the strongest specials available in Fire Emblem Heroes and is capable of turning the tides of battle given the right circumstances. Aether does not have inheritance restrictions, and can be given to all units save for staff-users. Its high impact effects are gated behind a long cooldown time of five turns, which nearly guarantees that the opponent will have charged their special before you do, perhaps even multiple times if they wield a Brave, Killer or Slaying weapon. Even with help, most duels do not last long enough to charge and use Aether. Instead, it can encourage a different playstyle: charge it on the first opponent, and unleash it on the second. Aether combines the functions of both Sol and Luna, with the added advantage of healing more health than Sol, as Luna boosts the damage dealt. Being worth 500sp, Aether is commonly seen on Arena sets to maximise score.

Aether's long charge time means it will rarely activate without skills designed to accelerate special charge time. Most commonly, Breath skills are seen in combination with Aether. A Killing/Slaying weapon combined with Steady Breath and Quick Riposte will guarantee an Aether on the unit's second attack. Aside from builds designed to maximise Arena score, Aether is most commonly seen on tanks with high Defense and/or Resistance who can use it to sustain over a long period of time. Like other healing specials, Aether is a great choice for longer modes where it can keep a unit healthy over a long period of time. Aether is great with high-attack units, but has poor synergy with Wrath since the damage boost will be activated less frequently. Healing from skills such as Renewal can help a unit last till the special is ready. Triangle Adept is a good skill to use alongside Aether: It can let a unit charge their special safely on a foe with disadvantage, to unleash on a neutral-color foe.

The biggest weakness to Aether is its long charge time. It is possible to reduce this charge period, however all of the methods used for Aether can be used to charge faster specials even more quickly. A unit attempting to charge Aether may have to suffer two specials from the opponent before they can get a chance to unleash their own special. Thus the easiest way to defeat a user of Aether is to maximize on a special such as Bonfire or Iceberg, with a faster charge time while boasting high power.