High-cost Characters you sit on for multiple turns are a liability: they clog your hand and kill draws
This, of course, includes stores like Walmart and Target, but MTGs reach continues to expand
Adrix and Nev, Twincasters Adrix and Nev, Twinscasters is another popular Merfolk commander, but this one certainly doesn't need you to be in a dedicated Merfolk deck
The more control you add, the less you'll be subject to random chance, and the better a winning strategy you can reliably incorporate at any given time
Ranger of Eos - As I described in my entry in Dimir House Guard, this creature is really only good for getting Seers
It seems like a linear deck that has some cute things it could do, but it requires too much setup