is not really explored. On the one hand, this is likely that any "essence" of an enemy is a rune, but on the other, this could mean Elden Ring Runes some runes are long-lasting and/or are draconic in nature, as dragons once ruled over The Lands Between.
This makes sense because some Rune items are called Golden .
(Golden Order?) or Hero Runes. Enemies whose eyes glow, for example, drop more runes, and that could support this aspect LOLGA.COM of Elden Ring's level up process. Of course, there may be no answers here, but Rune Bears and Red Wolves have, no doubt, some draconic features worked into their very essence.