If you have multiple copies of “Dark Snake Syndrome”, the effects are cumulative.
Both players take damage during the Standby Phase of the controller of the “Dark Snake Syndrome”.
If “Imperial Order” is active, you still increase the damage from turn to turn for “Dark Snake Syndrome” even though no damage is dealt.
Netrep Rulings:
If “Dark Snake Syndrome’s” effect is negated, “Dark Snake Syndrome” will continue counting Standby Phases for the purpose of inflicting Damage, but Damage will not be infl icted until “Dark Snake Syndrome” is no longer negated.