Of course many people can craft it, it's actually easier to find the recipe than most rare blue weapon (as it can be bought in TAS).
As any other T3 crafted weapon, you need 20 shards, 20 Zemorian Bronze,20 Royal Gold, 20 Darksteel, 20 Tumbaga, 20 Black gold, 20 Purlwire and 20 celestial flux (resource vendor) for 2 ingots.
Then you need to craft, for Maniacal Harm, the Acheronian Steel Ingot (Soldier) and the Eventide Ingot (Mage). Then you need to find a
small ferric fod (base weapon) and the
recipe for the maniacal harm which you can buy from the vendor between The Keeper of the Artifacts and Thoth Amon.
It's a rather long process, and unless your guild can craft T3 items, I would suggest you to go for an Ibis, it will be less of an hassle
You may find a few people selling ingots, but it's very rare, as most guilds who can craft Ingot have no-selling policy and also a queue so important they barely have time to craft for their guildies, so imagine for outsiders (you need 2 weeks to complete a crafting process, so it takes 1 month for 2 players, techically a year for 24 players).
You'll find all details about T3 crafting (recipe, materials, and such)
here.