There maybe some form of blood involved as well to Official Metallica 38th anniversary 1981 2019 signature shirt. He only drink wine. If he doesn’t need food or drink, then he surely does not need ‘wine’. That wine could be blood. Akin to the paste, the Jojen-paste Bran eats to kick start his powers. Beric is also in a cave surrounded by Weirwood roots. These caves are the former dwellings of CotF and numerous bloodsacrifices may have happened there previously and the power of magic could very well be stronger there than other regions. All these factors would help keep Beric functioning. I am sure that some form of fire is also used or present in each resurrection.
Official Metallica 38th anniversary 1981 2019 signature shirt, hoodie, sweater and v-neck t-shirt
Best Official Metallica 38th anniversary 1981 2019 signature shirt
Blood for fire. Fire for blood. Beric uses his blood to light his Official Metallica 38th anniversary 1981 2019 signature shirt. The fact that a complete life is not sacrificed to resurrect Beric each time correlates with his relatively average powers. He continously gets killed and fails in the one on one duels. The Shadowbabies disappear once their assassination tasks are complete. They are ephemeral and not enduring. Beric is similar. Perhaps, he would be much stronger and more powerful if a complete life was sacrificed for him each time. Similar to the dragons, or Robert Strong.