Long time Elysium player. Lag has been getting worse. It's definitely not computer or internet lag since I can flash jump and use client-side skills while streaming to twitch or on discord.
The weird thing about this lag is that you appear to move around the map on other players screen but attacks are not registered on their screen.
During the lag (happens unexpectedly), you cannot attack or loot which will hurt dps while bossing as well as other gameplay eg. muto PQ. The moment lag ends while bossing, all the map hazards will appear at once for as long as you're lagging out. In worst circumstances, all your teammate's attacks will be registered at once (along with map hazards) within a short amount of time and cause disconnection.
One recent incident I experienced was during Will phase 2, I server lag out for 36 seconds, upon "coming back", all of my teammates' attacks for the duration while lagging out got registered for the next 4 seconds and ultimately dc. Example: https://www.twitch.tv/videos/611519144