A/N: So, after reading through a series of Micaiah x Zelgius/Black Knight oneshots, I became a devout shipper of the two. And that turned into a whole thing with Fire Emblem Heroes, which is this story! Hope you enjoy!
Kiran had just received a new supply of orbs, and was eager to spend them in order to summon more heroes to fight in for the Order. While at first he wasn't getting too much, only repeats of units he had summoned, and even then, they weren't very good, his luck eventually changed, thanks to the sudden unintentional intervention of Micaiah.
This intervention happened to be that as she was walking by the summoning stone, being lost in thought, she tripped and dropped her Thani tome. Kiran, startled by the noise, rushed to her side to help her up, but in doing so, he accidentally pulled Breidablik's trigger. The special summoning orbs shot out, as usual, but on their way, to him, they appeared to have gathered some energy from the presence of the tome in the summoning area. The orbs eventually struck the stone, and with a large puff of smoke, and a much brighter flash, a person appeared in front of the stone. A person wearing a distinctive black suit of armor, and carrying a massive sword.
Of course, the knight introduced himself as the Black Knight of Daein, and Micaiah, who had been up to that point simply frozen in shock, ran up to him with alarming speed, and pulled him into a powerful, loving embrace. She had ended up burying her face in the plates of his armor, and, weeping, she exclaimed, "Oh, Zelgius! You have no idea how much I missed you!" Zelgius, in turn, replied, "And I you, Priestess of Dawn. After the son of Gawain struck me down, my soul seemed to live on, and I could feel all your distress, all your grief. But no more of that. I am here, and that is all that matters. Although, that begs the question: what is this place that I have been brought to?" Kiran, realizing the question was most likely addressed to him, responded, "This is the Kingdom of Askr, Sir Zelgius. I won't lie, it's rather… interesting. In fact, I don't think you would have been here, were it not for Micaiah's… intervention." Zelgius turned to face the Legendary Summoner of Askr, and asked the obvious question: "And what did it entail?" Kiran then explained what had happened in the minute before, and Zelgius seemed to lose a little bit of the stoicism he usually held firm. Glancing down at Micaiah, he said to her, "Yune herself blessed those orbs you enchanted, I'm sure of it." Micaiah nodded, but then she remembered that her tome was still in the circle. But before she could run to grab it, Zelgius used Alondite's massive blade to shuffle it towards her. "You need not strain yourself anymore. Whatever you need, I will attempt to provide." Micaiah would not stand for this, however, and replied, "I think that won't be too necessary. And besides, that works both ways, Zelgius." This statement confused Zelgius, until Micaiah explained, "If you are ever hurt in battle, I will be there to heal you. I promise." The knight immediately understood, and replied, "Very well, Micaiah. Although I suppose we made this oath already…" Micaiah shrugged. "Ah, yes, that fateful night when you appeared out of seemingly nowhere and swore to protect me or die trying." As they were saying this, Kiran cleared his throat. "Sorry to break up this reunion, but I was trying to summon for the latest version of Ike that the orbs can bring." Micaiah froze. "Oh no…" Zelgius was, of course, very concerned seeing her completely frozen in fright. "What's wrong!?" he demanded, to which Micaiah replied, shakily, "D-did you n-not h-hear him? Th-that l-latest v-version is th-the only one who accepted y-you! All th-the oth-thers are f-from b-before!" With that, she promptly fainted, her mind having begun to run through all the possible scenarios, then deciding to shut down in response. Luckily, Zelgius caught her before any real harm could be done, and, after asking Kiran where the nearest infirmary was, he left.
A/N: And that's Zelgius getting in! But obvious problem: Kiran's probably not going to be able to summon the one Ike who accepted Zelgius, so there will be issues. Can the Black Knight and the Priestess of Dawn find a way to make the other Ikes know tolerance? Well, that's the question, isn't it? That won't happen until much later.