Grouping

[Rias]

Triple-channel pyro cast/trance is better for taking out a single target, absolutely, since it's all the fire focused into one place. Triple-channel pyro nova is glorious to behold against multiple foes, though!

[criticalfault]

I was thinking more about splashable attacks. i wonder if they bounce just as easily or if they have a cap on bouncing..

[Rias]

Splash damage from some of the exploding/splattering/arcing casts is fun, but it packs nowhere near the punch of a pyro nova - particularly a three-channel pyro nova - which hits all enemies for the same potential amount of damage. Even a single-channel pyro nova hits harder at minimum than the maximum damage of any elemancy splash damage (which isn't guranteed to affect every hostile in the room), with the one exception of lightning. Lightning requires 3 different mancies, and its accuracy is also based on the average of these (so requires much more skill to raise offensive accuracy). It also takes more energy to cast than a nova.

A pyro nova can still do a significantly higher amount of damage than lightning arcs (not the main bolt), two- or three-channel versions doing higher minimum and maximum damage. Novae are also guaranteed to target everyone not in the caster's group, while lightning arcs may not even happen, or may not target some hostiles, based purely on luck.

And of course, novae are extremely hard to dodge, bypassing the usual combat mechanics that lightning needs to overcome in order to land that initial hit before any arcing can occur.

In summation: Pyro novae are super awesome and well worth using!