- A 60 seconds CC, with posibility to make it instant cast
- Decent Stun, Knockback and slow for kiting.
- Self Heal or the posibility to heal others.
- Bubble to make up for light armor (sometimes it's even better than heavy armor)
Merc: doesn't have interupt
Sniper: doesn't have all-around 60 sec CC, doesn't have self/others heal.
TLDR, Sorc is like Merc + Sniper combined together, as far as the range of abilities is concerned