If you just play seed teams you can get top 50-100 for the event and get 5-6 tokens for the store . That is better than the 2 tokens you get in boss events. The main difference is no CP, no HP, and no 4* progression covers. You can get significantly more iso and a lot of heroic and standard tokens to farm your 2* though
This isn't the Thor release. It's kind of a bonus extremely bad chance at getting one cover. They said there will be a real release starring on nov 2nd. Even if you finish first overall there is less than a 0.2% chance of getting a five star and only 1/3 of those will be Thor.