Champion in general has 3 aoes,
the bubbles around the champion, during which he can cast other skills
the flames round him, during which he can't cast other skills (but it possible to turn on bubbles and than flames)
the 'circle' on the ground - nice range and stays for a couple of seconds, during which he can cast another skills
In the case of ch/m there is also damage once his hp bubble shield goes off/is destroied
Or the lvl 60 elite, which is bum bam, 1kk hit

.
Not to mention that ch/m (actually each champ combination) has a ranged attacks...
Unless Dysantic remembers the name of the skill that killed him, its really hard to guess which one was used
btw, ch/m has 100% more mdef elite skill, and a lot of damage mitigation skills