These "Missions" should be called "Tilt Quests"
I don't know what to say, really. First of all, these missions are heavily geared toward pre-made groups, instead of Solo players.
I mean, players are forced to win 3 games with 3 different champions on Onslaught for 1 token. Then forced to win another onslaught game with an A rating. The ratings from the three games won earlier do not count.
A champ shard or an Icon is not worth the tilt, believe me. It's not worth the time, and not worth the energy. Stay away from this one.