This kinda slipped by under the radar and even I didn't notice it until now, but some summons just got a pretty big buff in JP. Basically, any 4*+ summon worth its salt hits twice now. Overall multipliers haven't been changed, so this effect is minimal against high level, high-RES content, but summons just became amazing for grinding dungeons. Dealing 9999x2 against the Dream Stooges on classic mode was very, very cathartic to the Zenny who had to restart an entire FF6 file due to them as a kid.
With decent de/buffing I bet this could be pretty useful against high end content, particularly for clearing out adds (like, this would have been beautiful for Velius). Pretty neat.
EDIT: Leviathan down. Team was the usual. Would maybe have been difficult if I hadn't heard y'all complaining about his dungeon mode and having that key me into the fact that I should reflect him. Reflect just utterly wrecks him, though. Hasted Zack/Bartz throwing Thundara/ga spellblades at him was kinda ridiculous.
The fight was noteworthy in that there was one turn where I just said fuck it and had every single character use their SSB.
Also, honed R2 Full Break, because why not. What am I gonna use those Thunder/Ice orbs for? Holy? Honing Quetzaqotl since summons that hit weakness are potentially super good now? Actually yeah both of those would have been good ideas but, fuck it, YOLO.
EDIT 2:
For reference, the list of summons that now hit twice (overall damage modifier is the same as previous):
Shiva
Ramah
Ifrit
Syldra
Leviathan
Maduin
Valefor
Ixion
Alexander
These summons hit twice AND got a boost to damage modifier:
Quetzaqotl
Bahamut
lol maybe bahamut may be worth crafting now
y'know if you can ever find Major Summon Orbs outside of an orbfest