Permafrost the Archmage

When Permafrost enters return it to its owners hand unless you have a Glacial counter. If Permafrost is returned to your hand this way
you may search your library for a card named “Cryogen, Below Zero Prison” reveal it and put
it into your hand then shuffle

Permafrost’s Protection - Whenever a creature you control dies if it didn’t have a Glacial counter return it to the battlefield tapped with a Glacial counter