To get you to buy more battle cube refills.
Well that goes without saying. Though it won't work on me. This event isn't something I'd pay for. Not with this style of game anyway. Without any real PvP with strategy involved and something to gain, winning this event is not very critical. Don't get me wrong. I like the idea of it and I appreciate the devs for implementing it.
I only bother with it at all because its a good way to get a lot of cards fast. Good for leveling, good for collecting. Which is why my inability to draw a single class 4 card over the last 3 days has really soured this event for me.
Yeah, I got a few good 3s that I can now work on leveling and scanning. But I can get most if not all of them in the regular game. Getting a few 4s was really the goal for me this event. With it coming to a close and getting increasingly harder to stay in it, it doesn't look like that'll happen. Pisses me of slightly.
Hopefully they do another event sometime soon. Rage of the Dinobots anyone? I'd do a few things differently in the first couple rounds to have more energon cubes saved up for the last round when they start to run dry.