Absolutely fantastic! Not only do they add even more eidolons to play around with, such as Genies, Oozes, Oni and even Mages, but they also allow for variant Eidolons such as the Devil, Linnorm and Archon variants of Demon, Dragon and Angel respectively. Some of the variants could use a little more options, since they usually just change one of the eidolon's abilities. The class archetype introduced here also gives an option for a full martial Summoner that not only makes Tandem Strike finally viable, but also introduces a lot of fun ways to fight in tandem!

The extra 'manifestations'- new ways to manifest eidolons that change how the eidolon is summoend- are amazingly inventive, and very fun to play with. Incarnate lets you play the fantasy of summoning a mighty creature for a shorter time like a Final Fantasy summon, Rider lets you fully play around with having a steed eidolon, Splintered has your eidolon become three different creatres instead (for all the kobold-trenchcoat lovers out there) and Synthesist takes Meld into Eidolon and adds so much more onto it. The eidolon physical alterations options present ways to change your eidolon's attacks and form too, though they aren't as major an overhaul in the Eidolon's kit (save for the swarm form alteration).

This Teams + book also does something none of the others have seemingly done, featuring items to work with Summoners. This includes a new staff, a speed-boosting invested item and a pokeball-like throwable item!

Teams + consistently makes great stuff but THIS has been amazing to read through. I highly recommend you get this for all the summoners on your table.