To cast a Chaos Bolt, you need one Ember. One Ember is equal to five incinerate casts, which means about 5-10 seconds of ramp up.
In ADDITION, a fire mages instant cast PYROBLAST crits for MORE than Chaos Bolt does. Fun facts.
In ADDITION, the CAST is long as hell, this DEGRADES the true damage of the spell. For example. You do AS MUCH DAMAGE per three seconds with an INSTANT cast AIMED SHOT and two ARCANE SHOTS.
I capitalized things to make it easier for you to read. Please stop QQing in the warlock thread, we are not over powered, you just don't understand class mechanics and how to put a true value on spells.