Upgrade your Flask of Wondrous Physick with the Bloodsucking Cracked Tear, which you can only obtain in Elden Ring's Shadow of the Erdtree DLC content.
How to Get Bloodsucking Cracked Tear | Elden Ring Shadow of the Erdtree
The Flask of Wondrous Physick has a great name and even better intentions. Elden Ring's one-time-use-per-life potion allows your player to concoct a magical concoction and receive two massive stat-boosting benefits for a short time.
Tears are very common in the base game Elden Ring, but in Shadow of the Erdtree you can only obtain them in a very specific way: by defeating Furnace Golems.
The Bloodsucking Cracked Tear can be found in the Ruins of Unte after defeating the Furnace Golem in the area. Once defeated, the Tear is one of the items the creature drops, along with the Furnace Visage crafting material.