ElectricDragon
Explorer
Mass Phantasmal Killer already exists but is called Weird (9th).
Charm Monster is 4th level.
It is possible that I missed some but here are the Mass spells from the SRD:
The first number is the level of the spell for that class, the second number is the level of the base spell (non-mass version) and the third number relates the levels of difference.
Wizard/Sorcerer
9-Mass Hold Monster-5=+4
8-Mass Charm Monster-4=+4
7-Mass Invisibility-2=+5
7-Mass Hold Person-3=+4
6-Mass Owl's Wisdom-2=+4
6-Mass Fox's Cunning-2=+4
6-Mass Eagle's Splendor-2=+4
6-Mass Cat's Grace-2=+4
6-Mass Bull's Strength-2=+4
6-Mass Bear's Endurance-2=+4
6-Mass Suggestion-3=+3
4-Mass Reduce Person-1=+3
4-Mass Enlarge Person-1=+3
Druid
9-Mass Cure Critical Wounds-5=+4
8-Mass Cure Serious Wounds-4=+4
7-Mass Cure Moderate Wounds-3=+4
6-Mass Cure Light Wounds-1=+5
Cleric
9-Mass Heal-6=+3
8-Mass Infllict/Cure Critical Wounds-4=+4
7-Mass Inflice/Cure Serious Wounds-3=+4
6-Mass Inflict/Cure Moderate Wounds-2=+4
5-Mass Inflict/Cure Light Wounds-1=+4
6-Mass Bear's Endurance-2=+4
6-Mass Bull's Strength-2=+4
6-Mass Eagle's Splendor-2=+4
6-Mass Owl's Wisdom-2=+4
Bard
6-Mass Fox's Cunning-2=+4
6-Mass Eagle's Splendor-2=+4
6-Mass Cat's Grace-2=+4
6-Mass Cure Moderate Wounds-2=+4
6-Mass Charm Monster-3=+3
5-Mass Suggestion-2=+3
5-Mass Cure Light Wounds-1=+4
As you can see the level difference is usually 4 (25/33), 3 is the next most common number (6/33) and a 5-level difference exists in two places (Mass Invisibility and Druidic Mass Cure Light Wounds).
I would say that such a metamagic feat would require at least +4 levels normally. My own campaign answer though was another metamagic feat called Multiple Target where the levels added equaled the original spell level for each additional target; e.g. Charm Person cast at three targets would be 3rd level. Not nearly as good as a Mass spell, but then those already exist as spells and any wizard worth his salt would research a new spell to fulfill his needs (e.g. 5th-Mass Charm Person, 1 person/level)
Ciao
Dave
Charm Monster is 4th level.
It is possible that I missed some but here are the Mass spells from the SRD:
The first number is the level of the spell for that class, the second number is the level of the base spell (non-mass version) and the third number relates the levels of difference.
Wizard/Sorcerer
9-Mass Hold Monster-5=+4
8-Mass Charm Monster-4=+4
7-Mass Invisibility-2=+5
7-Mass Hold Person-3=+4
6-Mass Owl's Wisdom-2=+4
6-Mass Fox's Cunning-2=+4
6-Mass Eagle's Splendor-2=+4
6-Mass Cat's Grace-2=+4
6-Mass Bull's Strength-2=+4
6-Mass Bear's Endurance-2=+4
6-Mass Suggestion-3=+3
4-Mass Reduce Person-1=+3
4-Mass Enlarge Person-1=+3
Druid
9-Mass Cure Critical Wounds-5=+4
8-Mass Cure Serious Wounds-4=+4
7-Mass Cure Moderate Wounds-3=+4
6-Mass Cure Light Wounds-1=+5
Cleric
9-Mass Heal-6=+3
8-Mass Infllict/Cure Critical Wounds-4=+4
7-Mass Inflice/Cure Serious Wounds-3=+4
6-Mass Inflict/Cure Moderate Wounds-2=+4
5-Mass Inflict/Cure Light Wounds-1=+4
6-Mass Bear's Endurance-2=+4
6-Mass Bull's Strength-2=+4
6-Mass Eagle's Splendor-2=+4
6-Mass Owl's Wisdom-2=+4
Bard
6-Mass Fox's Cunning-2=+4
6-Mass Eagle's Splendor-2=+4
6-Mass Cat's Grace-2=+4
6-Mass Cure Moderate Wounds-2=+4
6-Mass Charm Monster-3=+3
5-Mass Suggestion-2=+3
5-Mass Cure Light Wounds-1=+4
As you can see the level difference is usually 4 (25/33), 3 is the next most common number (6/33) and a 5-level difference exists in two places (Mass Invisibility and Druidic Mass Cure Light Wounds).
I would say that such a metamagic feat would require at least +4 levels normally. My own campaign answer though was another metamagic feat called Multiple Target where the levels added equaled the original spell level for each additional target; e.g. Charm Person cast at three targets would be 3rd level. Not nearly as good as a Mass spell, but then those already exist as spells and any wizard worth his salt would research a new spell to fulfill his needs (e.g. 5th-Mass Charm Person, 1 person/level)
Ciao
Dave
