it's clearly related on where are you goind to use obviously, but, in situation 1 where the creatures are weak/neutral to fire damage i would go with:
| spell 1 | spell 2 | spell 3 | spell 4 |
---|
spell name | exevo vis hur | exevo gran flam hur | exevo gran vis lux | exevo gran flam hur |
and expose weakness every 16sec that it afect the monsters
on the other hand, there is a case where fire damage and/or energy damage isn't that worth, than i would swap the spells for properly runes that are the strongest for the spawn, an maintain the expose weakness