Quote Originally Posted by Unregistered View Post
what do most people prefer from a friends eidolon the 40% character attack/hp 20% or the 40% element attack one?
It's circumstantial. For example, if I run Garuda and then Jorm as a friend eidolon, I get immediate access to ATK -10% in Advent Ragnaroks. Stacked with my existing -55% ATK, that reduces all incoming damage by 2/3. Layer that on top of +20% HP and strong heals, and my team is nearly unkillable.

But in general, the HP eidolons and elemental attack eidolons have good synergy, and you should be running one of each. With a maxed team you'll be losing about 10% damage by running an HP eidolon, but that's generally worth the added durability. Losing even one character before the first Burst in a Ragnarok can easily derail a run, and added HP helps avoid that.