How to do the massive spike burst?
Generally these people are afk, picking daisies, running glass themselves or a combination of the 3.
You can stealth, blink next to the target, mirror blade, mantra of distraction, shatter as soon as the clone appears, mind stab and that will usually take off a good 15k all together.
However you have literally only one weapon skill left without switching and no utilities to gtfo after. You probably also want to up your power for hitting that hard, if you can get up to 3k your mirror blade will do ~2.5k per hit. Blame WvW stat inflation for that.
There are different ways, buy mostly those numbers are against enemy glass cannons (ie thieves or other mesmers), especially with the mirror blade nerf.
Easiest is (stealth) – Mirror Blade – Blink – (MoD) – Dodge overhead + F1 (3 illusion shatter) – Mind Stab
Take Mental Anguish, boon strip and other damage boost sources (sigils, food, traits).
You can also try with the mantra damage boost but personally I don’t like that and find DE more useful overall.
Ok thanks for the tips guys, I will try them out!