Thrasir

Thrasir is a character in Fire Emblem Heroes. A general of Hel, she shares a name with the founder of Embla.

Profile
In ancient times, Thrasir became the first empress of Embla, forming a pact with the Dragon Embla. With the dragon's blood, she gained the power to close portals to other realms. Much like Askran royalty as well as her own descendants, she can bind Heroes to contracts.

In Book III, Chapter 1, Thrasir makes her debut as a general of Hel, attacking the Order of Heroes during Hel's invasion of Askr. She retreats upon defeat, while Alfonse and Sharena consider the fact that they are now fighting the ancestors of both nations. In the following chapter, she once again appears leading Hel's army, and is forced to retreat without a word. She faces the order again alongside Líf. Once both are defeated, and retreats through a portal he creates for them. After the order discovers they are in a ruined Askr, she faces them again before retreating.

Eventually, she reveals that, just like Líf is Alfonse from an alternate timeline, Thrasir is a future version of Veronica, one in which her kingdom also suffered major casualties, including her beloved older brother Bruno. Knowing her own way of thinking, Thrasir intentionally left a book about the weapon the "forbidden heart" created in her version of Embla in order to lure Veronica to the Temple of Blood and kill her counterpart. However, Alfonse, aware that she would likely verify their demise, intentionally sprung the trap and so that they could strike her down. When asked why would she fight for Hel, she bitterly says that no one but Hel can restore Embla and that's why she follows her.

Once Thrasir is defeated and apparently killed, Veronica says that she has no real synpathy for her since one of them had to die. She does, however, promise that Hel will be defeated.

Later, it is shown that before the events leading to her demise, "Thrasir" made a promise to "Líf" that after balancing the cohort of the dead and reviving everyone in their realm, both of them would talk together again as allies and not enemies, which "Líf" agrees to.