Probably those set trees, I myself have 2 of those (unfortunately long time ago (before teleports) i deleted 2 of them (had 4)) and they are my main city's mana income (for full mana bonus you needed only 3 pieces of the set).
@SoggyShorts Like they listen.... thy listen only when it fits well in their plans (increase their income or cover some nerf) with some small exceptions like mass manufactories production and small things like that.
@Enevhar Aldarion Well, removing ranking points would result in a massive lost of income (some players can pay a lot to be first).
Ranking points are the only remaining goal of mine i haven't fulfill already (moving up in the ranking and see how high i can get). If it wasn't for them, i would have 0 remaining goals left in the game and probably left already.
ps: Yes, the bears artefacts are the only ones i actualy need (it is cheaper to feed 1 lv 10 Panda than two lv 1 pandas to get 0 cooldown in tourney.