One of the runes, if not THE rune most closely associated with Odin/Wotan.
The rune represents his countenance with his windswept cloak behind him when he is in his warrior-priest aspect. It is therefor a rune that is very valuable in shamanic workings as a lot of shamanic work had (has) to do with the well being and survival of the tribe they belong to. That is not to say that there is no such thing as “dark” or destructive shamanism because there most certainly is that, but these are things we also need to see in their right context for instance “if you want peace then prepare for war”. Being harmless is not the same as being peaceful.
All runes can be used to bring destruction as well as they can be used towards life affirming goals. And Ansuz in particular is a tool that can be used as a tool to accomplish either, by ridding yourself of fear of death.
Shamans die a thousand deaths in one lifetime.