Means the spell you are thinking of using should be perfected before you even consider this.

Daevryn isn't saying it happens 24/7 as a lowbie invoker, he is saying that when you are fighting an invoker the amount of commands it takes to win/survive the fight for both sides allows for an extremely low margin of error. It is your responsibility therefore to perfect your damage spells (which will always 9 times out of 10 happen faster than some idiot at mist wraiths at level 15 if you put any sort of effort into it with a 23+ int character.)

A conjurer at level 27 kills people the same way an invoker does, the trick is to not tackle the first rager or village applicant you see who is ALSO hunting for free kills, with your crappy regear. You kill whoever got a lucky pit loot and work your way up slowly until you can nuke the other career lowbie playerkillers.

Finally, Daevryn won't say it outright but this will only work on a certain set of targets that slowly expands dependent on your gear, available damage reduction and whether you can squeeze a rescue in between a missed bash to extend the length of the fight by 1 or 2 commands.

The counter to this exact tactic against invokers and muters is wearing between -20 and -30 svs spell and keeping enough gold on hand to heal. Then roflstomp them as normally. When you are below 40, people with more than -20 svs spell are exceedingly rare (I myself have probably been zapped by Daevryn before, and I was probably one of the individuals with a return potion and a minimum of -15). It's the same reason transmuters can use neuro at all on the majority of the population, svs paralysis simply isn't a consideration for the vast majority of the population. There's too many other straight laggers to gear for it.