@Buffman but which highest rank? Logically, your highest rank is the higher of the 2. Also the wording one of your mystery's granted spells is ambigious. You could already have had a granted spell the feat can maybe give more of.
Maybe I'm just being nitpicky. Is only one specific highest level spell slot really a big deal already at level 12? Maybe it is for Chain Lightning.
@Khanzarate So just Battle Medicine and potions? @gronk