The voice actress for Mog in both Japanese and English (Sumire Morohoshi and Ariel Winter, respectively) shares the voice for characters in other Square Enix works: Marlene Wallace and young Kairi, who are also cute, small characters.
On a related note, Ariel Winter also voices Gretchen from Phineas and Ferb. It would have made things if Mog and Hope interacted with each other.
Captain Cryptic is voiced by Dave Wittenberg (aka, Kefka Palazzo) in the English version, which makes his quiz question regarding Terra Branford extremely hilarious with that knowledge.
Weapons: (Can be obtained from Chocolina's shop for 0 gill once purchased. Improved versions of these weapons become available throughout the game once you buy them.)
Serah's Weapons:
Seraphic Wing◊ - Heals Serah as it deals damage to enemies.
Nabaat, Ultros & Gilgamesh, once bought, will have a chance to say "Final Fantasy XIII-2; the story so far," along with everyone else.
Additional story content:
"Heads or Tails" (Sazh's story) — Explains Sazh's sudden disappearance and his attempt in finding Dajh through the power of fortune. Adds Sazh (Role: Synergest, Feral Link: Cold Blood) as a party member when cleared. Also unlocks two new Serendipity card minigames, Chrono Bind and Serendipity Poker.
"Snow: Perpetual Battlefield" (Snow's story)
"Requiem of the Goddess" (Lightning's story) — Story segment shown through Lightning's point of view as she struggles against Caius. Adds Valkyrie Lightning (Role: Commando, Feral Link: Legion of One) as a party member when the battle is cleared with five stars.
The "additional voices" section reads as practically a "who's who" of every major active voice actor out there that isn't already part of the main vocal cast, including pretty much the entire English cast of the playable characters of Eternal Sonata and many who had major roles in previous Final Fantasy' titles, such as Hedy Burress.
Final Fantasy XIII-2 was originally supposed to tie-in with Type-0 being set 900 years into the future still with Valhalla being in the year 999 (the same year Type-0 is set in) but the idea was cut. The idea of humanity being reduced to a single village stuck in a Time Crash was retained for Lightning Returns.