Originally Posted by
Slashley
74% is a bit low, but you'll get it up.
Short answer: absolutely.
Long answer: depends on content and your friendlist.
If your friendlist is full of Jack o Lantern AND you need the HP, then Dullahan is good. Otherwise, not really. Double Jack o Lantern should be better almost always.
Ultimately you'll want to use the gacha 100% Dark elemental attack Eidolon, which isn't even out yet in JP. And well, getting that thing is... yeah, no.
So realistically, your goal is to get Jack of Lantern... and five high attack Dark element Eidolons. Sadly, the latter isn't possible since even JP doesn't have a single event 1900+ atk event Dark Eidolon. As such, your goal is to get five high attack Eidolons (while gathering LMB Darkness Eidolons for the eventually upcoming 50% Elemental attack Darkness Eidolon which requires 5 other Darkness Eidolons equipped, not out on JP yet).
As for feeding the +1 Eidolons... Yggrasil is highest atk Eidolon on Nutaku at the moment and also has a somewhat decent on-use (+600 HP). So, feed either Yggrasil or Dullahan for +99. Dullahan is the weakest Darkness Eidolon as far as attack goes, but I guess HP isn't THAT bad.