Here's How To Beat Liadri
I would also add to this: if you feel like you are falling behind in terms of movement with the AoE pattern, and you just barely make the next safe zone (due to being crippled or whatever), turn around and go the other direction when the next zone appears. It’s easy to forget that the next safe zone is sometimes much closer in the opposite direction when getting caught up in the chaos of the second phase.
I’d say that the most important things to take against her are mobility skills (blinks, leaps), invulnerability/evasion skills, condition removal, and healing.
Mesmers are one of the best choices against her because they have all of these – Blink, Blurred Frenzy, Phantasmal Disenchanter, and significant healing. S/F or S/D eles are also a good candidate because of their invulns, condition removal, mobility, and powerful self healing.