I'm not sure if there is a specific fanfic exactly about that. There are tons of Fire Emblem fanfics out there, but this particular combination might be a bit rare. You could try searching on fanfic - specific websites like Archive of Our Own or FanFiction.net to see if it exists.
One popular storyline could be Naruto and Tiki teaming up to face a new and powerful enemy. Maybe a villain from another dimension who threatens both their worlds. They would have to combine Naruto's ninja skills with Tiki's unique abilities to defeat the foe.
The 'Kon Tiki' novel is mainly about Thor Heyerdahl's epic adventure on the Kon - Tiki raft. It tells of his journey across the Pacific Ocean to prove that ancient South Americans could have reached Polynesia by raft.
Thor Heyerdahl penned the 'Kon Tiki' novel. He was the one who actually carried out the Kon - Tiki expedition, and then he wrote about his experiences in this novel.
Well, Tiki Tom's fictional characters could be anything. It could be a group of space explorers or mythical beasts. Without more specific details, it's hard to say exactly who they are.
Naruto's chakra - based powers, such as his Rasengan, could be combined with Tiki's more magical powers. For example, Naruto could use his chakra to enhance Tiki's spells, making them more powerful.
In many Fire Emblem Grima x Tiki fanfictions, the theme of trust is key. Since Grima is a character that is often not trusted, the development of trust between him and Tiki can be a major plot point. Another common theme is the idea of prophecy. Given the rich lore of Fire Emblem, prophecies related to both Grima and Tiki can be explored in fanfiction, such as how they might fulfill or defy certain prophecies through their relationship.
You can start by looking on fanfiction websites like Archive of Our Own (AO3). There are often tags related to 'Fire Emblem', 'Grima', and 'Tiki' which can help you narrow down the search. Another option is FanFiction.net, although the tagging system might be a bit less precise. You could also check out some Fire Emblem - related forums where fans might share their favorite fanfictions about these two characters.
One possible plot could be that Allen is a curious character who was exploring an old haunted house. His tiki ghost hand, which has a mind of its own, reaches out to touch an ancient door. As it tries to pass through the door, it gets stuck. Allen then has to figure out a way to free it, perhaps by using some magic spells he learned from a local witch.