After the Nightfall

This emblem unlocks after you beat the Time Trial times of each Nightfall Strike; these times need to be obtained after Forsaken's release. The site destiny.report has a great tool to track your Nightfall times, I've included the link below. Thanks to the "DestinyTheGame" subreddit for figuring out the times for each hidden Time Trial. Likely no longer obtainable after the release of Beyond Light and the DCV.

Sign of Celebration

In 2024: Donate $7 and choose this emblem from the emblem vault during the 2024 Bungie Day period (2024-07-09 to 2024-07-29). In 2023: Donate at least $100 during the Bungie Day Giving Festival 2023.In 2022: Raise (not donate) at least $777 during the 2022 Bungie Day Giving Festival.Previously: Purchase anything on the Bungie Store between Bungie Day 2019 (2019-07-07) and 2019-07-13.

The Reaper

This emblem dropped upon completion of the "Triumphant Reaper" Triumph. No longer obtainable after Gambit Prime was retired

The Collector

This emblem dropped upon completion of the "Triumphant Collector" Triumph. No longer obtainable once Gambit Prime was retired.

The Sentry

This emblem dropped upon completion of the "Triumphant Sentry" Triumph. No longer obtainable after Gambit Prime was retired.

Resonant Chord

Purchase the Destiny 2 Original Soundtrack Digital Edition from the Bungie Store.

The Invader

This emblem dropped upon completion of the "Triumphant Invader" Triumph. No longer obtainable once Gambit Prime was retired.

Hubris of Niobe

Complete the full Niobe Labs puzzle; once complete the emblem will drop. No longer obtainable after the forges entered the DCV.

Warminded

Obtained by accessing all forty (40) Sleeper Nodes on Mars. No longer obtainable after Mars entered the DCV.

Operation… Oboe?

These emblem variants can drop once you reach a certain score threshold in a Nightfall. The drop rates are unknown, but if you are looking to get this variant, you'll want to go for a high score run (get the highest score possible) in the related Nightfall, then do speedruns of the Nightfall until the emblem variant you want drops. Note this is a variant of the emblem named after the Nightfall it drops from.

A Cold Wind Blowin'

Complete the "Rogue Light" Triumph during Season 04. Once you redeem the Triumph, the Drifter will sell the emblem (only during Season 04).

Simulant Spring

Complete all Triumphs during the Revelry 2019.

Answered Call

Complete the Triumph "Super Celebratory" during The Revelry 2019. Once complete, redeem the reward from Bungie Rewards.

Emblem of Synth

Purchase any item from the Bungie Store during the Season of Opulence.

Death to the Deathless

This emblem randomly dropped upon completion of this Nightfall. No longer obtainable since this strike has entered the DCV.

Vex Scholar

Obtained by equipping the full "Kairos Function" set on a Warlock. No longer available as a result of Mercury entering the DCV.

Blood of Izanami

Complete the "Reunited Siblings" Triumph, which required you to kill 500 enemies with Izanagi's Burden at the Izanami Forge. No longer obtainable after this forge entered the DCV.

Helping Hand

This emblem drops once you complete your first Guided Game raid encounter as a guide.

Blade of Bergusia

Obtained by completing the "Clean Up on Aisle Five" Triumph, which required you to kill 500 enemies with Threat Level in the Bergusia Forge. No longer obtainable after this forge entered the DCV.

Anno Panthera Tigris

Redeemed from the heybox app. Skarrow9's video with instructions in linked below for a full walkthrough. Also given away as part of a series of SteelSeries giveaways in early February 2022.