Well, most of the time fury seems to be a waste of pillz...
It can be quite useful in many situations:
You have a character with +X life per damage. Using fury means doing at least 4 damages and sometime even more (Kenny with +2 lifes per damage mean you'll get 6 more damages!).
If you apply lesson #2 "thinking in less than 4 rounds", fury is a good and quite unexpected way to reach your KO
Dont use fury at all if you really needs to win most of the forthcoming rounds. You better save thoses 3 pillz to get an attack advantage.
I like using Kolos when the opponent has a damage reducer card like Nistarok and it is in a NO RANDOM room. You can just put 2-4 pillz on and you will probably win and get some easy damage if he assumes that you fake. If he puts on a lot of pillz and wins, you have a lot more pillz than your opponent and will probably win,
A fury can be great for a fast KO. For example, if you have Striker and Robb. You manage to win with Striker, and want a fast KO. Oh no! You only got 4 damage cards, you can't do a 2HKO. Oh wait! You can just fury with Robb!
Striker = 6 dmg. opp's life is 6.
Robb = 4 dmg + Fury = 6 dmg. 6 dmg.+ 6 dmg. = 12.
Now you can KO the opponent with Robb.
But you should always check how many pillz you have left to increase the attack of Robb.
If for example you only have 4 pillz, (1 left after using Fury) you probably won't have enough attack to take down the opp. card, so be alert.
I use fury in almost every match.. Either for the 1hko with Kolos or for the bloodsuck of Mojo/Kenny or if I've successfully bluffed my Kolos and cost them 9 to 10 pillz I furry 1 or 2 of my "Filler cards" turning even meager Sargh into 5 damage that coupled with the other 2 victories I'll be netting earns me battle points and peace of mind
I never use fury unless i have to or in dt if im sure to win i would play the amount of pills needed and fury on say zatman for a quick ko .
as for fury i see it as a noob tactic i only use it in life or death situations .
and when i say noob tactic i dont mean that bad against anyone its just when someone uses Rolph 1st round get it through then they play Bristone 10/10 they play briston fury same thing goes for Petra Uranus combo
There's a lot of advice not to use fury on the first turn, but there's one situation I find where it works really well. Say you go first, and you have Sting in your hand. Playing her right off is a 10 power, 7 if your opponent has a Stop Opp. Ability. A lot of people won't even fight her, thinking they can make up the 4 damage pretty easily. Even if they do pill against her, 10 power is tough to beat. Maybe 2 or 3 pillz to increase her attack to 30 or 40, and another 3 to increase her damage to 6. Paired with one or two other 6 damage cards, and you have 6 pillz left and multiple opportunities to frighten your opponent into blowing his pillz so you can finish him off without a problem.