I updated the Rerolling Guide with the new section What’s the difference between the +100% and +120% eidolons? and added links to character portraits to assist rerollers in spotting the +100% and +120% eidolons.

I acknowledge Pigeon's request for a different label for these new eidolons, but I'm sticking with "+120% eidolons" for now because this is more meaningful to new players than "2019 Gatcha eidolons". The character profiles in-game don't list the date the character was released, but they DO list the elemental attack bonus they provide with 0 limit breaks. Accordingly, I'll change the label to +140% when the December eidolon update hits.

While I'm not super-active these days, I do intend to keep the Rerolling Guide up to date. This should require only one update per year since the DMM version allows us to see a year into the future, which is very doable.

What’s the difference between the +100% and +120% eidolons?
The +120% eidolons have the same base bonus of +100% elemental attack, but gain an additional 4% elemental attack for each sub-eidolon of the same element that you have equipped, for a maximum of +120% elemental attack. A December 2019 update is expected to augment this bonus to 8%/sub-eidolon (maximum +140%). The +120% eidolons also have different summon effects, so in some circumstances a +100% eidolon may be preferred over a +120% eidolon (e.g., Hraesvelg’s -20% DEF debuff will often increase damage more than +20-40% elemental attack).

The Dark and Light +100% eidolons have a +80% base bonus, reaching a maximum of +100% with 5 matching-element sub-eidolons.

Both +100% and +120% eidolons are further augmented by limit breaks, increasing their base bonus or max matching-element bonus (Managarmr, Anubis) by up to +20%. Limit breaks can be added by using the eidolon limit break item obtained from Guild Damage Competition events (coming in August 2019).