For users: OK, I fixed it. You just have to put the following .pk archive in the same directory as media.pk and media1.pk to see the final dialog in english.
For the devs: The exact cause is that the cue "[You see Reetor sitting on the sandy shore of the island, unable to move as each effort shoots unbearable pain through his shattered bones. You see Torne, the leader of the Water clan, his body adrift on the waves that do not even try to wash it ashore. You see Andre, who has finally managed to get out of his castle. An Earth mage, resting upon a thin black rock rising up from the sea. You see the redheaded Liz, whose heart, in defiance of everything, is still beating within the blazing depths of Oros. All the mages are looking at the Outer World Castle - you can feel it in you. And their eyes are glimmering with faint and desperate hope.]" has a length of 0x28
7 characters and not 0x28
8 which is the value written in d073_loc25.dmb.
Last note: I just regret not being able to compress when repacking.
EDIT: for those who don't/don't want to/can't have a 1C account, you can find the fix here:
http://www.megaupload.com/?d=5Q02F3B6
EDIT (2017): re-up:
http://www.mediafire.com/file/4zvw6t...s_media100.zip