That being said, there's a few unique promo cards whose effects can't be recreated by any regular option, and either way the full list of Promo Cards in TCG Pocket is around 100 cards now, despite starting out with less than a dozen of them
Thinking Ink Colors Represent Good and Evil The official Lorcana description states that no ink is inherently good or evil
Welder lets you put two Fire Energy Cards onto a Pokemon and draw three cards afterward
Bleeding Effect Cairn Wanderer Crypt Champion Extus, Oriq Overlord Firja's Retribution Indominus Rex, Alpha Kamiz, Obscura Oculus Kathril, Aspect Warper Marneus Calgar Rayami, First of the Fallen Shadrix Silverquill Snapdax, Apex of the Hunt Snapdax, Apex of the Hunt Soulflayer Squall, SeeD Mercenary Urborg Scavengers Wretched Bonemass
This allows Pokmon like Buzzwole ex and Guzzlord ex to attack much quicker, increasing the odds of winning a battle
You dont learn it once