Er, I don't see the contradiction, let me be a bit clearer:

Basically, keep the power within certain ranges

# of targets: between 1 and 5, or a small, well-defined area of effect
Range: between point-blank range to line-of-sight if it's a projectile or beam. No hitting things you can't even see or infinite range, or the ability to penetrate any number of barriers.
Damage: your spell shouldn't be able to guarantee a kill. One-hit-kills on mooks and monsters can happen, but it cannot be guaranteed.
Rapidity: spells should not be able to be fired endlessly, there should be some sort of cooldown or recharge associated with them. You can have 'spray' type attacks that can be fired for an extended period of time, but you have to stop eventually, and it should be offset by either low damage, or something.

I think Sailor Mars' attack fits because it is a single target, line-of-sight attack that does decent damage, but is not fired in quick succession.

EDIT: Whoops, I guess I didn't watch to the end of the video, I hadn't noticed how large the pillar of flame got towards the end.