Deadlock's player statistics are already indicating a hierarchy and difficulty curve to its heroes in its closed beta.
According to the site Tracklock, Seven is the most popular on the roster, sitting at over two and a half million games played, a pick rate of 92% and a win rate of 57%. This is likely due to a combination of the hero's powerful abilities and ease of mastery, which have led to nerfs already.
Other popular heroes in the MOBA/third-person shooter include Haze, Lady Geist, McGinnis, and Warden, with Haze the second most popular choice for players at just under two and a half million games so far - the other characters lag a decent ways behind.
At the other end of the spectrum sit Grey Talon, Paradox, Vindicta, Viscous, and Yamato. Many of these, particularly Viscous and Yamato are not considered beginner-friendly, but can be lethal, so we'll see if they rise in popularity as more players flock to the title and rack up more hours of mastery (thanks, PC Gamer).