Small Battle Mage base Health Regen rebalance
Now that Growth Stat and % base Stats exist and most champions have been sorted into Subclasses it should be time for Riot to take another look at most base stats and decide if they're satisfied with the chaos.
Battle Mages, as the AP Fighter class somewhere between Mages and Tanks, should have higher base Health Regen because they do not have access to Life Steal like Fighters do and don't scale with Health like Tanks do. Catalyst of Aeons on its own doesn't make up for that.
So I suggest sorting Battle Mages' base Health Regen into three tiers:
##Tier 1 -- 7 +0.95 Aurelion Sol, Karthus, Rumble These champions have no heals or shields or in Rumble's case he's melee.
##Tier 2 -- 7 +0.7 Malzahar, Ryze, Viktor, Taliyah These champions have small shields and in Taliyah's case she's very mobile.
##Tier 3 - 7 +0.6 Anivia, Cassiopeia, Vladimir These champions can heal themselves up or in Anivia's case her egg grants her a whole lot of Health Regen.
In all cases but Viktor's these would be buffs. In Viktor's case he ends up with the same amount at level 18 but loses out on some until then. I excluded Swain because he's getting a VGU soon.
In addition to this I'd change Rylai's build path to include Crystalline Bracer instead of Ruby Crystal and have the item offer 50% base Health Regen.