Oh but they didn't improve anything ^^
Essence/Aden is simply a recycle of 99% of the old animations and/or skins.
They had to do a work from 0 for basically...nothing. Of all the things you see right now, most of the animations are slighty changed or recolored.
And yeah, this server is currently the last gasp of official l2. Cause EU servers all failed, same goes for NA, just look at the Classics: dead in kr, dead in eu and dead in na.
Awakening servers are still running in KR and so they do in EU and NA.
Essence/Aden servers are still running in KR and so they do in NA and EU, altho EU servers are basically dead with probably 100- unique players left.
Sayha goes down based on how much XP you do, so it's normal that if you gain more XP it goes down faster.
For example: Lair of antharas, mobs there gives from 500 to 1kk XP per mob and you lose 1% sayha per mob cause that's the cap.
In other zones, like plains, you lost 1% every 3 mobs, where you earn around 150k (50k +/- per mob)...so i'm quite sure that there's a XP amount required to drop 1%.
So let's say that 150k XP = 1% sayha, if you hunt mobs giving you 100k or 130k, you would still need 2 mobs to drop 1% but that's 200k-300k XP, while if you hunt mobs giving you 50k XP, you will drop it faster cause you're getting 50k per mob and you wont be able to "abuse" the cap.
But i might be wrong, cause in the end sayha drops fast even at low levels when you don't earn 50k per mob..i think it's both X-XP required or/and X-mobs to drop 1% sayha.