There isn't really a "true spiritual guardian spirit of the soul" type business when it comes to picking a fursona.
It's just what you want it to be.
You like bats and find them interesting? Make a bat character, give it a personality.
If you don't feel you connect with it just make another one.
Most people go through multiple fursonas and just keep the old fursonas as OCs for stories or stock characters for roleplays or whatever else.
Just go with whatever animal you want or have an interest in, you don't have to force yourself to try to fit some cookie cutter spiritual furry description, just do whatever makes you happy. Pbt, don't feel like you connect with any current animals? Make up your own, whatever, it's your character, the only boundaries are in your head.