What can be answered now
The keyword is present in the research plan, but that does not verify the encounter's mechanics. No retained source provides a complete Zareth Arn walkthrough. There is no supported basis here for a safe spot, an exact damage threshold or a guaranteed equipment combination. Each of those claims remains 待确认.
Do not borrow another encounter's mechanics
Official announcements sometimes describe changes to other named bosses. Those entries apply to the encounters they actually identify. A documented slam or movement adjustment for another boss cannot be assigned to Zareth Arn. Doing so would create a plausible-sounding strategy without supporting evidence.
Evidence required before expanding this guide
A full guide needs direct, version-matched evidence of attacks, phase transitions and successful responses. Any proposed build also needs an observed result rather than an assumption based on its name. The current materials do not supply those observations for this keyword. This page remains a clearly labeled research gap, while the build guide covers the separate mechanics that are documented.