Dont need to nerf Fates XP, just need to make them harder as the levels goes by. Currently its as easy as spamming the same ability over and over (OH WAIT).

Give more damage/HP/defense to the mobs, so that each of them work as a mini-mini boss and that when the fate has a real boss, make it really like one. Some fates with 15m to be done end before the 14 minutes mark, now this is really insane... Make every fate last at least 5 minutes or so and probably impossible to solo...

Also mobs around the world needs some improvement in xp, currently killing to get xp only works for the 1-5 levels. :/ Partying to kill mobs on the wild is one of the best things in mmos...