The compound $AgF_2$ is an unstable compound. However,if formed,the compound acts as a very strong oxidizing agent. Why?

(N/A) In $AgF_2$,the oxidation number of $Ag$ is $+2$,which is highly unstable.
Therefore,it rapidly gains an electron to return to the more stable $+1$ oxidation state.
$Ag^{2+} + e^- \rightarrow Ag^+$.
Because it readily accepts electrons,$AgF_2$ acts as a strong oxidizing agent.