To start with, here's a quick summary of how the format works.
How the randomization works:
How the stats work:
How the rewards work:
The current meta is experimental, and as such it's going to have problems. It's likely to go through a lot of revisions before it's reasonably balanced, and that's what this thread is for.
If you've encountered a build that doesn't make sense, please either report it here or via PM. Examples of what I'm