I was thinking of traps or spell storage (pre-casting), and I came up with some ideas

1) Pre-cast a spell, and it goes off within 10 turns
2) Cast a spell, and it goes off once a specific situation happens (pre-defined trigger)

Hmmm... this is venturing into the realm of multiple attacks. I tried to stay away from this.

Pre-casting for it to go off in 10 turns: You can have crazy numbers of attacks. I would add some sort of claus that sets its roll to 15 exactly (or 10 or whatever exact success would require in that situation) ... meaning that against a defending opponent or if conditions change the spell will not work.

Triggered condition: You can already do this for any spell with restrictions.

After some time has passed and my re-reading this thread by fluke chance.

Pre-casting to gain multiple attacks (well.. more like one charged Effect per Meta-effect) is definitely possible within the rules and need only be stipulated with the add 10 Turns duration Meta-effect (and being furthur defined that it's charaged to be used at an utterance until it disipates in 10 Turns.)

I'm not certain of my thinking at the time of writing the earlier post but as of right now, and as long as people understand that that the 10 rounds duration applies only to a single Effect and not the whole Talent, I do not see any real problem with such an Effect (other then a ludicrous amount of Opposed Rolls).