Riot, please. Enough with the "Play X games" missions.
You had two great ones this week. Play 20 different classes and play 20 different origins. A very solid couple of missions that rewarded people for trying out new things.
You also had 3 separate "Play X games to round 3-6" missions. The third one was 10 games. And it's...well...imo it's the shittiest mission type. Yeah, not all of them can be great, but this kind is just...it's insufferable. It turns a unique gamemode into a grindfest.
It's fine if there's just one of them and it's smaller (5 games to 3-6 is a bit of a delay, but it's no more than the Orb requires for max points). 10 games would have been...okay, if it was by itself. But it was 3 of them in a row ending with the 10 games.
A better alternative, imo, is the "collect x interest" or "play X of A or B". Again, forces variety, it's small enough, and, most importantly, doesn't feel like I have to grind out games. It feels like something I should be able to pick up from just playing, and doesn't feel like I'm playing games just for a reward. Even if, on average, it takes me 10 games to get those champions or that interest, it feels better than being forced to play 10 games because I feel like my actions have control over it. 10 games to 3-6 is a trivial requirement that feels boring and like I don't have to try for it, but I can't improve it either, except by surrendering games at 4-1, which I'm fairly sure is behavior you don't want to encourage.
Missions can be a great and useful thing, but...That mission I don't think could be saved short of divine intervention.