It would have been interesting if Poppy could have forge her weapon....
I mean, she was a black smith. They could have done it in a way that her weapon damage and shape/skill would vary according to the materials used.
Materials could come from minons, jg monsters, baron, dragon and even champs. For example, if she kill a certain amount of mages, her hammer would gain cc and add magic damage to her attacks. If she kill more adcs, she would gain attack speed/range. If she kill more melee champs, she would gain more damage an AOE
She would only be limited to one of those upgrades so she would have to choose wisely which champs she wants to farm.
I don't know, just some random thoughts.