I actually made a version of this to put in the imaginary set I was making earlier. This is probably too powerful in its current form, while the part I put in the imaginary set was tad more toned down. The one in my set practically screams symmetry, with every cost from casting cost, equip cost and activation costs set to two mana. I recognise that as the better card, but I expect to tone down the casting cost to 1 eventually. I think that 6 mana to initially give a creature an ability permanently is probably too much, but 4 mana to be able to repeatedly do it is still sound.
But every card has a starting point in the idea path, and obviously, this is among them. Notably, it can be pretty ridiculous if you have the right mana at the right time for the right reason. And yes, I do mean it to not end at end of turn. While this could lead to eventual messes, I think it is fine as is for an imaginary card.
With that being said, I'm a big fan of artifact and equipment, so I expect to make artifacts that work without colored mana, but work splendidly when fed the right mana. In addition, I expect to pour ideas in about modifying a variety of crazy aspects while trying to keep the entire set coherent and inherently playable in Apprentice.