-> The weapon used on Lulusia is a Vegapunk invention called "Mother flame" and Imu only wanted to test it. When the gorosei asks why he wants to test it on Lulusia, he answers "because it's close".
-> In the seraphim page the marines say "Unleash the seraphims, Crocodile is here!". It's probably when Croc and Buggy met in the flashback in chapter 1058.
-> When Sabo called Dragon, he was using a den den mushi from Lulusia as a bridge. He says it's probable the government thinks he's dead because the signal they intercepted was from Lulusia.
-> Ivankov has a book that seems to explain that one of the 20 kings was named "Nerona Imu".
-> Ivankov thinks Imu used the Ope Ope because he thinks he's the same person from the Nerona family 800 years ago.
(It's not totally clear whether the book talks about Nerona Imu or the immortality operation)
-> Dragon and Ivankov can't believe Vegapunk would give something so devastating to the government. They wonder if they have an ancient weapon and if that's the case, why did they wait until now to use it.
-> Saint Figarland Garling is a king/champion (王者) who had an important role in God Valley. He's the leader of the holy knights.