[Sunred]

So on the Saber side of the poster, I have decoded the rider moji the best I can and so here goes. The bolded letters are what are actually on the poster and those that are not are me making an educated guess based on context.

SEKAINI KIKIGA SEMARISHITA SO NO TOKI TADASHIKI YUUKINO KOKORO YAMIWO TAOSEBA IDANIARU NIHIKINO

And it trails off. So to translate, this message is saying "When a righteous heart of courage defeats the darkness at a time when danger is lurking towards the world, two great ...". Keep in mind the word 'hiki' is used in Japanese as a method of counting non-human creatures, so nihiki means two non-human creatures. For example, if someone said "nihiki no ryu" it means two dragons. Back to the topic, based on this my assumption is that:

1. A possible movie exclusive wonder ride book involving two animals or mythical beasts will be the key to defeating the movie exclusive threat
2. A temporary truce between Saber and Calibur giving us a double rider moment
3. Touma gets to wield both Brave Dragon and Jaaku Dragon through an arbitrary movie exclusive item/gimmick