Improved boss battles
The only example of one currently in-game but not well known is Malrona. She seems to have a hidden mechanic that allows players to significantly increase their damage against her if they are already suffering from her Poison. Using this mechanic, you can then reflect her Venom Blast to deal… well, I’ll let the screenshot below speak for itself.
Arah path 1 end boss is similar. Although its so easy for everybody to hold the crystals for reflection. But guardians and mesmers can reflect as well for hits around 100k. However unprotected he would 1 shot people.