[Edi]

Currently it is impossible to add secondary effects to weapons via modding. That option may or may not become available in later patches. Hence, you cannot add paralyzation or other effects. What you can do is take either Mind BLast (86, 12 and dmg) or Mind BLast (311, 10 an), use the #selectweapon command and assign aoe 1. If you do this, you should mod those R'lyeh units that use the now modified mind bLast to use the other one, and use the modified one for the new units you have in mind.

Edi