mesmer wvw,tpvp,pve ?
Different builds work for different things. Mesmer can be effective and useful in all of the above depending on what you’re running but it’s best to keep in mind that what you run in PvE will be different from what you run in PvP.
For mob tagging, you wanna slot Mantra of Pain for AoE spamming. In tPvP you wanan run a shatter or lockdown Mesmer, in zergs glamours and mantras hold your team down.