The timing sequence for Damage Reflect for Empress Cygnus.

That's because it is.

When you attack her solo, she casts reflect as defined in the game files, roughly 80 seconds from the last cast, but when attacking as a group, she can pretty much reflect whenever the hell she feels like, sometimes spamming in rapid succession, with no rhyme or reason, making it impossible to time. We've chalked this up to just her being glitched.

So, it is best if one would to solo it, means, only ranged classes, ds, shadowers and mage can do it currently. (Paladins, heros, dks would face more challenge?)

Technically, whichever hits first will allow full use of dark meta orbs to be used on her. So order isn't big deal really. If you bind/crash whenever she does an attack, that's a 100% guaranteed success, can't mess that one up ever really (exception of CD issues). If she does a DR buff and you go and use crash/bind afterwards well that's kinda your fault for being impatient. To put it simply, she attacks slow so make use of her slow attacks and bind/crash when she actually does something. Bind has a huge range, so it never hurts to stand back and wait until the right time to cast it, crash however has limited range and the only time you really care about the range issue is when she uses too many tornado + flame DoT attacks and you gotta run back to heal yourself.

The only real problem I've ever had was when our timing sometimes goes out of sync and we forget when the next effect CD is worn off, like for instance using bind every 1min, which sometimes we bind too early and it would actually "miss." When the miss happens, it doesn't even matter if you used crash or bind, if the party wasn't paying attention and thought your skill worked (most people won't even bother watching that your skill missed) they would've kept attacking until they potentially killed themselves and/or you.

edit: well you can scratch off the 1st paragraph of mines really, its kind of like what you said already. When it comes down to how few people and if it ever only comes to just 1 crasher and 1 binder, I'd suggest bind > crash mostly for v2 summon. Just to get that CD kicking in and so nothing goes wrong save for the person using it at the same time as DR buff or after DR buffs appears which shouldn't happen usually unless you messed up the first time.

So technically for a squad, Bind 1st followed by Crash when crash expires. Then during the R, everyone sits back relax.