The spirit of a creature trapped in amber cannot escape to it’s afterlife / next incarnation / whatever.
Such trapped spirits can be contacted by those who know the right rituals and magical power derived from them – typically the power to control one individual of that species.
Can by quite powerful if the creature is a colony insect (ant, bee, wasp, etc) – simply control the queen and you command the whole colony.
A massive trebuchet constructed by the reigning tyrant, it can hurl the heaviest loads of any trebuchet to date and is the most destructive, non-magical weapon currently in existance. The Thought of Warwolf setting up on their lawn has quelled many a rebellion.