How Are You Using Rank-Up Resources?
Just curious how other people feel about this, but as someone who's Paragon and on the verge of becoming Valliant (I'm one Necropolis path away now that I've explored Act 8), I've decided that I don't want to use catalysts on 6-stars anymore. Rank-Up Gems are seemingly more and more common, and when Rank 4 7-stars are introduced to the game, 6-stars are going to be left behind.
The only 6-stars I plan on ranking up any time soon are Kate for Necropolis and maybe Bullseye for Battlegrounds, and both of those can go all the way to rank 5 using rank up gems.