Do the Eidolons lead up to something, i.e. Do we collect all 4 to unlock a 5th?

Dr. Crab

Sorry if this has been asked, but was this supposed to be this next Deathless type thing or is it just get the 4 and thats that.

SoSA__Remake

Most likely gonna be just the four, since it was stated that the eidols are gonna be in the basic pool in the future. No involvement with the titans