Ephika

Ephika is the family ship between Ephraim and Eirika from the Fire Emblem fandom.

Fire Emblem: Sacred Stones
Ephraim and Eirika are the twin prince and princess of Renais. They were both gifted the Sun Brace and Moon Brace respectively, the items which allow them to gain access to the Renais Sacred Stone they are fated to protect as the royals of Renais. Later, they are gifted the twin weapons of Siegfried the Lance and Sieglinde the Sword respectively.

They both have a series of supports which can result in a paired ending. Their supports reinforce the care and love they have for one another as brother and sister. They also reveal tokens of affection that they have for another, such as Eirika's childhood habit of stroking Ephraim's face. They end on the note of vowing to always stay with one another.

Their resulting paired ending has them rebuild Renais together with Ephraim as King.

Fire Emblem Heroes
This information recalls from the mobile game Fire Emblem Heroes and as such as a semi-canon to non-canon nature with the mainline games.

In a map that introduces players to Sacred Stones characters, Ephraim comments on people misinterpreting his and Eirika's relationship. Implying that they are not incestuous, however Eirika has flavour text which refers to the Japanese myth of twins being reincarnated lovers.

Additionally, they share a Duo Unit together as children.

Eirika was crowned the runner up of the 2021 Choose Your Legends voting competition in the women's division and was given a unique Brave unit. She is styled after Ephraim and uses his lance as well for this alternative form as a playable unit. Meanwhile, Ephraim's Brave unit - as he was a winning unit in the 2018 men's division of the Choose Your Legends campaign - is styled after their father.

In Brave Eirika's Forging Bonds dialogue, fellow Sacred Stones chara Seth comments on how Eirika's kindness and Ephraim's strength are a duality that their deceased father embodied at as a great leader and that if either twin was to follow in his footsteps, they have to adopt the other's virtue. Ephraim ought to take Eirika's kindness whilst Eirika has to utilise her strength better on the battlefield.

Fanon
Ephika is a controversial ship due to the incestuous nature of it.

Fandom
FAN FICTION
 * Eirika/Ephraim tag on AO3
 * Eirika/Ephraim tag on AO3

Trivia

 * The signature weapons Siegfrid and Sieglinde which Ephraim and Eirika use respectively refer to Norse mythology; in Richard Wagner's interpretation, these of these myths, the twin characters are incestuous.
 * Eirika claims that Ephraim taught her to use a sword yet he is a lance unit, implying that her use of stabbing swords, such as rapiers, is due to his influence.