Positives of an I/L?

On 3 mobs fire demon becomes better than CL, also I've heard that ultimates have pretty good DPS if there is more than 1 target

Let's take a look at it in DPM to consider attack speeds.

CL DPM on three targets: 210*2.19=459.9*88 attacks per minute = 40,471.2 base dmg/ second

Fire Demon DPM on three targets: 140*3=420* 84 attacks per minute = 35,280 base dmg/ second

On 4 hits, yeah fire demon is slightly stronger.

And as for ultimates versus CL on three targets:

Blizzard: 600*3=1800*21=37,800

Meteo: 620*3=1860*21=39,060

On single target, paralyse is the strongest AM skill. On mobs of 2-3, CL is the strongest. Any more than that and its between the ultimates and fire demon.