Quick Answer
Guildrun Sal best upgrade is 待确认 because the current keyword material folder does not include a dedicated Sal source file. The safest source-backed advice is to prioritize the route that supports Frost application, Duelist synergy, and attack speed, because those are the repeated Sal themes in the Red Rift and tier-list material.
Why Attack Speed Matters
The Red Rift transcript says Sal needs attack speed items so she can level or ramp. The tier-list transcript also describes a scenario where early Sal plus attack speed support can become extremely strong. That makes attack speed the clearest build direction from the available material.
Attack speed matters because Sal's value is tied to applying pressure repeatedly. If she attacks too slowly, her Frost and debuff value may not show up before the fight is decided. This is especially important in harder fights where timing matters.
Frost and Duelist Direction
Sal appears as a Frost source in best-comp material and as a Duelist-related pickup in Red Rift notes. Frost can help reduce enemy defense and support boss damage depending on the team. Duelist relics and debuff interactions can multiply her value when the board supports them.
This does not prove one named specialization is always best. It proves the safest upgrade direction: support Frost, attack speed, and Duelist/debuff triggers. Exact spec priority is 待确认 until a current Sal-focused source is added.
What Not to Claim
Do not publish “Sal's best upgrade is X” unless the source material directly supports X. Do not invent current numbers, item names, or specialization values. This page should be updated when a dedicated Sal material file is collected.