Recheck the damage type of the abilities you copied
The 0.21 patch changes Shadowstrikes, Mark of Shadow and Edge of Darkness to Umbral damage. It describes Umbral as bypassing resistances entirely. This is a specific reason to review an old setup that selected bonuses around the abilities' previous damage types. It is not proof that every ability in every Thief configuration now deals Umbral damage.
The July development post had announced that the new damage type would also be used by Thief. The later 0.21 release notes identify the concrete affected abilities. Use the released change as the stronger reference when the earlier preview is less specific. A complete list of current Thief mastery combinations is still 待确认 in the supplied material.
Keep Resistance Piercing changes in chronological order
Version 0.20.11 reduces the Thief Resistance Piercing Chance class bonus from 60% to 25%. It also lowers the stat's base value from 20% to 5%. These changes precede the Umbral adjustments in 0.21. An old screenshot can therefore differ from the newer setup for more than one reason.
The same older patch grants Deathbringer's Handwraps Resistance Piercing Chance. Version 0.21 then replaces that item with Deathspeaker's Handwraps. Do not assume that an older item's full tooltip survives the replacement unchanged. Check the current gloves and the damage types that your actual build uses.
Do not treat every triggering mechanic as the same stat
The 0.19.6 hotfix corrects a Fan of Knives Life Lost proc issue involving Additional Proc Chance. It also changes the listed Life Lost proc chance from 15% to 5%. That is a documented, ability-specific correction. It does not establish one universal proc formula for every Thief ability.
Instant Attack Chance is a separate compatibility concern. The 0.21 notes rename it Rapid Attack Chance and distinguish primary attacks from other abilities. A repeated-cast setup should be checked against that rule rather than using an unrelated Fan of Knives percentage. See the proc page and Rapid Attack explanation for the separate evidence.
Confirm the actual character behind an imported plan
Auto-Build can substitute alternatives when some required unlocks are unavailable. The 0.20.7 note also says changing class or origin makes it ignore the options tied to the replaced choice. Copying a Thief label therefore does not guarantee an identical final character. Inspect the imported abilities, equipment and rune selections before comparing damage.
The collected evidence contains no complete, controlled Thief performance comparison on 0.21.1. It does not prove a highest-clearing configuration or an optimal item in every slot. Those recommendations remain 待确认. This page deliberately gives the patch-sensitive checks instead of dressing a historical build up as a current winner.
A focused comparison to perform in-game
Identify which named abilities your old build actually uses. Check each current damage tooltip and then review the bonuses the equipment is intended to support. Keep the same ritual and main ability when investigating one changed dependency. This is a proposed review method, not a claim of local gameplay testing.
If a shared setup supplies a patch, origin, equipment list and exact rune order, retain those details together. If it omits one, treat reproduction as incomplete until that dependency is checked. In particular, a valid import string does not answer whether a Runeword is active. The runes page explains why Discovery can matter independently of the class.