Simple request: please bring the rainbow phoenix back as a Hall of Monuments reward if you had it unlocked in Guild Wars.
Lore-wise, the phoenix is an immortal creature, and the original rainbow phoenix recognized the hero’s worth and housed itself in your Hall of Monuments. 250 years is a short time to the immortal, and I imagine such an honorable creature would hold on to some loyalty to your legacy, remaining there to assist your descendants (especially in such dire need against the might of the dragons).
Game-wise, two of Guild Wars’ elite pets are already available through the normal point-based legacy system (the black widow and the black moa), and a precedent has already been set for carry-over achievements with the God Walking Amongst Mere Mortals title.
The Rainbow Phoenix was by far my favorite achievement from the original Guild Wars, my favorite ranger pet, and I would be overjoyed to have her back with me in Guild Wars 2. It seems reasonable for such a long, moderately difficult, game-wide achievement to carry on in Guild Wars history.
Thank you very much for your consideration.