Permanent Monster Familiars

I believe high leveled familiars also have more vitality, as Jr. Boogie dosen't last nearly as long as Mr. Alli.

I think that might just because higher-level familiars do more OHKOing, thus saving hits (thus saving vitality).

Actually both of you are wrong. The vitality decreases only when the familiar deals a hit. The only reason Jr. Boogie lasts so little is because it doesn't have an attack animation ,and attacks a LOT of times while a higher level familiar usually DOES have an animation, and it won't attack again until the animation ends.

So yeah, if you are a ranged character, attack from far enough, so the familiar can't get to attack, and you'll have an infinite familiar, basically.