When members of the forum are making jutsu for their character, or using pre-existing jutsu for their character, we want to ensure that there's a mutual understanding of what I'm calling "Standardized Drawback Awareness" so that no one makes a jutsu that's too out of the ordinary.
NOTE: When I say x post, that means x amount of the player's post or subject of the jutsu. Some jutsu don't have a duration, many don't actually, instead focus on increasing or lowering the technique's cooldown based on its rank.
SS-rank jutsu - Dependent on the type of technique, this is nigh demi-god/goddess power such as Madara Uchiha's Perfect Susano'o and Hashirama's Sage Art: Wood Release: True Several Thousand Hands. Normally, though the duration will be a tad lengthy, the cooldown will be twice if not three times as long; and there's almost always a drawback of some kind, a weakness that could potentially be exploited.
S-rank jutsu - Dependent on the type of technique. Duration of ten or less (usually) and cooldown of that much or more depending on what kind of jutsu it is.
A-rank jutsu - Dependent on the type of technique. Duration of seven to eight or less and a cooldown that's either a little less than that or a little more than that.
B-rank jutsu - Dependent on the type of technique. Duration of six to seven or less and a cooldown that's either a little less than that or a little more than that.
C-rank jutsu - Dependent on the type of technique. Duration of four to five or less and a cooldown that's either a little less than that or a little more than that.
D-rank jutsu - Dependent on the type of technique. Duration of three to four or less and a cooldown that's either a little less than that or a little more than that.
E-rank jutsu - Dependent on the type of technique. Duration of two to three or less and a cooldown that's either a little less than that or a little more than that, if this is a general skill it will likely vary.
Kekkei Genkai tend to last twelve posts with a twelve post cooldown. Though this can also vary.
End Note: This is meant to give you (the community) a general idea of what's expected of you. This isn't inscribed on stone (it's not absolute) but we don't want members veering too far off from the norm to maintain a balance of power in the forum.