FUSION ALTAR
The fusion altar's expedition gives gold, and will also help you form those rare ingredients for the armorsmith. On the other hand, the weapon forge is useless in the early levels, when you get to level 20 however, it's a different story.
You can switch to Weapon Forge by TH18 (you can make 5* weapons by then), but make sure you create as much 4* mats for the armorsmith before then.
I was wondering, is it worthwhile making 5* weapons even if it isn't part of a set or if i have an incomplete set?