It could have been done without your method if you knew the file formats to look for. That's how I got the ADXs out for the music.
Frame data was stored using a completely new format, unlike MBAC's, and completely custom. Given the size of the packfile and the diversity of the data types, many of which are custom, I call your plan impractical at best and idiotic at worst.
And yes an Eclipse form exists for most characters. There's also a mystery form (_3) that I'm not sure what is for. Additionally these is a set of boss characters (B_AKIHA, B_AOKO, B_ARC, B_HERMES, B_KOHAKU, B_M_HISUI, B_MIYAKO, B_RYOUGI, B_WARAKIA, B_WLEN) that are separate from the other characters.
Actually, here's a complete list of Eclipse modes:
AKAAKIHA_9.TXT B_HERMES_9.TXT CIEL_9.TXT MIYAKO_9.TXT SATSUKI_9.TXT
AKIHA_9.TXT B_KOHAKU_M_9.TXT G_AKIHA_9.TXT NANAYA_9.TXT SHIKI_9.TXT
AOKO_9.TXT B_M_HISUI_P_9.TXT HISUI_9.TXT NECO_9.TXT SION_9.TXT
ARC_9.TXT B_MIYAKO_9.TXT KISHIMA_9.TXT NERO_9.TXT V_SION_9.TXT
B_AKIHA_9.TXT B_RYOUGI_9.TXT KOHAKU_9.TXT RIES_9.TXT WARAKIA_9.TXT
B_AOKO_9.TXT B_WARAKIA_9.TXT LEN_9.TXT ROA_9.TXT WARC_9.TXT
B_ARC_9.TXT B_WLEN_9.TXT M_HISUI_9.TXT RYOUGI_9.TXT WLEN_9.TXT
And Crescent modes:
AKAAKIHA_0.TXT B_WLEN_0.TXT M_HISUI_M_0.TXT S_AKIHA_0.TXT
AKIHA_0.TXT CIEL_0.TXT M_HISUI_P_0.TXT SATSUKI_0.TXT
AOKO_0.TXT G_AKIHA_0.TXT MIYAKO_0.TXT SHIKI_0.TXT
ARC_0.TXT G_CHAOS_0.TXT NANAYA_0.TXT SION_0.TXT
B_AKIHA_0.TXT HERMES_0.TXT NECHAOS_0.TXT V_SION_0.TXT
B_AOKO_0.TXT HISUI_0.TXT NECO_0.TXT WARAKIA_0.TXT
B_ARC_0.TXT KISHIMA_0.TXT NECO_P_0.TXT WARC_0.TXT
B_KOHAKU_M_0.TXT KOHAKU_0.TXT NERO_0.TXT WLEN_0.TXT
B_M_HISUI_P_0.TXT KOHAKU_M_0.TXT RIES_0.TXT
B_MIYAKO_0.TXT LEN_0.TXT ROA_0.TXT
B_WARAKIA_0.TXT M_HISUI_0.TXT RYOUGI_0.TXT
And here's _3, whatever the hell it is. Probably special story mode stuff.
AKIHA_3.TXT HISUI_3.TXT MIYAKO_3.TXT SHIKI_3.TXT WARC_3.TXT
AOKO_3.TXT KISHIMA_3.TXT NANAYA_3.TXT SION_3.TXT WLEN_3.TXT
ARC_3.TXT KOHAKU_3.TXT RIES_3.TXT V_SION_3.TXT
CIEL_3.TXT LEN_3.TXT SATSUKI_3.TXT WARAKIA_3.TXT
Not all of the character entries have complete character data attached.
