Dantalion's Mirrored Mind

Upon completing a ritual chant while looking into a specially prepared steel mirror you temporarily place you mind inside the mirror.

While you are concentrating on the spell, you gain advantage on saving throws against any attempt to affect your mind through magical means.

When you succeed on a saving throw this spell gave you advantage on, you can use your reaction to try to reflect effect back upon its source. The reflected effect uses your Save DC for the class you cast this spell as. When you reflect a spell that required concentration this way, it breaks your concentration on this spell, even if the original source succeeds their save.

When you succeed on a saving throw that this spell gives you advantage on, you also gain temporary insight into that ability or spell, not enough to learn how to cast it yourself if it is a spell, but enough to know who or what the source of the effect is and exactly how the effect works. You gain this knowledge before you decide whether or not to attempt to reflect it.