How it works
The event SF banner (SP Mobile Special Region) works like this.
Everyday you get 1 free 10 svarog to use on specifically that banner. A free 10 roll only available for that day and will not carry over to the next day. This will go on for a week. You just start 1 bombing run everyday. That's 70 rolls for free if you do it each day.
In the banner pool, there's 1 ringleader. One of the 6 shown, randomly picked, and you can't know which one until you get them. If you happen to get the ringleader, the pool is available for reset and which rl is in the pool will be randomized again.