So by that, humor the new guy.
Ball Lightning, combat, indirect, physical, Area
Declare spell, declare target, declare force. Say it's 6.
Roll spellcasting. Count the hits. (say I get 4 hits). Keep all the hits, because it's lower than the Limit of the spell's Force.
Check for scatter (more than 3 hits, no scatter)
Check for hit. No dodge, but presumably "Run for your life" or similar interrupts that apply to grenades can give you a chance to reduce damage.
If you haven't reduced it, or gotten out of the AE some way, take the hit. Base DV is 6P v-6 or 6S v-6 (Damage depends on 'source or target'?) Combat spell, I'm assuming you're blowing stuff up, so base DV is 6P v-6.
If they didn't RFYL, 4 net hits, so damage is 10P v-6 to everyone hit.
You resist 5 drain. Stun if your magic is 4 or higher (your hits).
They resist 10P damage, using body+armor+nonconductivity. with -6 (to armor only, not body or nonconductivity parts of the pool).
Correct?