All tank powers grab aggro the same way. Each tank class has a single target taunt that cannot have aggro overwritten (except for scripted aggro drops) for 8-12 seconds.
Fire uses Fireball...each power has one, usually throwing something. Key to note here..all powers draw aggro, the need for a specific power comes into play if running 2 tanks & u want to draw aggro off the other one. That said, on fire I often have fireball in load as a defacto single target pull..ok its not a pull, but it makes em come running..just as good.
As they said all powers aggro. Even a buff that doesn't touch the enemy draws aggro. But there are also the single taunts that have been mentioned that are for taking aggro from another tank and should be used for that only. Usually the first power in the tree which is a projectile. But any power draws aggro. It's the game mechanic for all tank roles.
