Unbeatable
Win 5 of your own Solo Challenges after sending them to at least one other player.
You will need to create 5 Solo Challenges with at least one other friend to obtain this trophy. It is highly recommended that you set up the recommended settings of just adding one friend per challenge and having a minimum (30 minute) duration. Your friend(s) that you invite to the challenge must participate in the challenges (and they basically have to get a worse score than the target time or score to get a position on the leaderboard lower than you).