Ld cards are special in the sense that they can be only obtained by playing. Every two weeks they release a one 4 to 10 mission set for one of the existing Ld's or a new Ld. You get aprrox. a month or so to finish them, and they cause some artificial inflation within their clan (Money making tip)
Cr cards are cards removed from pack. Otherwise they're like normal cards (Eg, you can sell and/or trade them). And they're prizes in the Elo format for top 100. Staff picks out two cards every 6 months, give or take 180 days to go cr, for obvious or completely random-seeming reasons.
Events and lotteries are pretty much the same. Aslong as you qualify for it, you see a green button to join. If not, you don't. Only major difference is that in events you have to play by the rules made for you. Staff made events like Survivor 24 are a different deal, since you have to only play without applying separately.
Thank you for clearing it up, but still dont quite understand events, custom made, how they work, do you need to be in there in a specific time to battle others and so? And also, forgot to ask, what was the last clan that came out, when did it came and when can we expect a new clan?
With events there isn't a specific time, but you and the people you need to face have to be online at the same time within the beginning and end dates.
And they used to release two new clans per year. But there's been a year's gap between Skeelz and Vortex, and Vortex and Berzerk, so don't get your hopes too high.