Put it back in at #3, I think.
Looks good to me. How closely do we want to stick to Harm?
How about 10 hit points of damage per Misi, Will save halves. If it would reduce HP to zero or negative they get a Fortitude save to only be reduced to 1 hp?
Sounds good.
1d4+number of extra misi beyond 1? Aka 1d3+number of misi?