This is the sword Lucina and Chrom used from the video game Fire Emblem. It was 3D printed in natural PLA and then painted. I designed the model in autodesk inventor based on reference drawings I found online and using the book 'Knights of Iris' showing artwork from the game. I changed a few things on the falchion to make it more to my liking.
To print the sword, I cut the design in half (horizontal plane) and then in 3 pieces length-wise since it is a 40" sword and I have a 16" wide bed. At the interface between segments, I made V-slices to the stl so that when I go to solder and heat-weld the PLA pieces together, they have the most strength. This worked well for my Ike sword that I printed in a similar way. The whole sword took 2 days to print (multiple pieces throughout, so some dead time) and is about 650g in material.
Lucina / Chrom Sword files can be found on thingiverse:971540.
I didn't document this well while I did it but the idea is pretty simple. I used a soldering iron and hot air re-work gun to melt the pieces together. It is worth practicing on scrap pieces first because it is really easy to get the plastic so soft that it collapses into the support structure and ruins the look of the piece.
I would first hold the pieces flat and flush with each other and then drag a soldering iron tip through the interfacial seam to weld them together. Then I touched up the piece with the air re-work gun using smoothed aluminum foil on my fingers to smooth out edges (gently!).
The sword was designed with 'V' shaped ends on each piece so that they would fit together with more surface area. Square ends would have allowed pieces to be printed larger but would have had the downside of weaker welds.