The only reason I like giant killer is when you go oom you still have viable damage.
Also I agree with you that most people wont let you hit 4 times but if your team is also stunning them they really dont have much of a choice and it does tons of damage.
These are the reasons I prefer the 2 abilities but at the same time I can see where the frostshot can get an extra kill but I also like doing camps and not wasting mana on them when I dont have too.
Posted: Jun 19, 2015