Maybe not a spell, but I think it wouldn't be broken just to tack on the abilities of a familiar to an animal companion, or even a Paladin's mount for that matter. Just think a Paladin's warhorse could deliver smites!
(Cool image, but probably not that practical)
How you do it, I haven't...
I like this idea except that it allows a Champion Fighter 19 to take Wizard 1 at 20th level and instantly concentrate on three spells at once.
At this point your level 20 and have only 2 spells per day so no concentrating on 3 :), but I see your point. I was just trying to modify the previous...
I don't think that will work as you'd never be able to concentrate on any spell higher than 5th level.
For example you'd never be able to cast Blindness/Deafness at 6th level to affect 5 people....
I think it would be better to say you can concentrate on a number of spells = to your proficiency...
I don't know if anyone has suggested this or not but I like the idea of your familiar being able to concentrate on a spell for you.
I think it would give them more flavor and usefulness as well as becoming a worthy target in combat.
They would have to make concentration checks just like the...
I met with each player individually at the start of the game and had a high level diviner summon them individually. He gave each of them a common magic item, informing them the future rests on their shoulder's and to keep a watch on the other members because he doesn't know if he can trust them...