Im probably not the first to suggest this, there are so few original ideas, but i thought i would share just in case.
Just a quick idea that might help mix things up and provide a little extra fun now and again. How about Legendary Pylons. These would spawn say once every 20-30 or so NR's and GR's. Its simple its a Pylon that lasts the whole rift. It shows up near the start of the rift and lasts the whole rift. I would prefer that it be limited to Power, Channeling, & Conduit. Also if you choose to click on the Legendary Pylon , if its a GR then it will not count toward any leader board records and also doesn't count for achievements in GRs or NRs
Looks like fun, but honestly, what is the reason to have leaderboards and competitive GR or Challenge Rifts, when it doesn't count. Afterall this will be too OP to even consider a whole Rift with one Pylon Power. But I sure like the idea of legendary Pylons or Shrines, but it needs to be something unique and very fun. Maybe having a legendary Shrine that gives you 2000% on Legendray drop (like the community buff) for 5 minutes or so, or the EXP buff, something like this, and they should be random, like all the other Shrines and haunted Shrines and so on.