This card is interesting because the ability is probably one of the best in the whole game, but because of that the rest of the card works hard to keep it from being overpowered
This is concerning because once the package is shipped, there is no way of knowing if its waiting to be processed at PSA or lost in the mail
This human advisor has you Investigate (create a clue) for each opponent who lost life on your turn, and can create a flying token each time a Clue is sacrificed (the dreaded 'once per turn' clause rears its ugly head, however)
When you do get the effect off, its a gamble: itll mill cards from your opponent until they reveal a land, and the equipped creature gains +1/+0 per card revealed
My first try for a legendary creature / Background pick might be Candlekeep Sage and Abdel Adrian, Gorlons Ward to generate many tokens
You can find the cuts in the sideboard of the final upgraded decklist, over on Moxfield