Malcrof said: Some events do offer covers as a node reward, webbed wonder and hulk are 2 of them.
Pants1000 said: Bonus heroes are the best option we have for targeting specific characters. It works well for 3*, it works but is slow for 4*, and it’s ridiculously slow for 5*. I did recently get my 13th Okoye cover from BH though, so it is possible.