Itd be fun to pair Karlach with Acolyte of Bahamut for some Dragon action or Criminal Past to put commander damage kills on the table
For example, if Lyse Hext enters on a turn where you've already cast two noncreature spells, she'll have double strike immediately
The first is energy counters , as exemplified by Satya, Aetherflux Genius
Players who buy Collector Boosters enjoy them, and we have no plans to change anything about them (well, big picture, they're customized to fit the set they go with, so they do evolve over time)
Phasing is probably the most foolproof way to make sure that nothing bad happens to your creatures, because not every board wipe merely destroys creatures these days
Now you've left the "building" phase and you're into the "tuning" phase