Some of these on line games should be classified as a gambling site. You have to pay to buy these packs that may or may not advance your character. Some people pay hundreds of dollars or more to keep a character at the top level. Some competitions can be fierce, especially if a person invests a lot of money into the character.
These games are insidious because they say they are for free, and sure at some level they are but once a player gets hooked, these sites know what it takes to keep them paying up.
I have no idea about those sites.
Thank you for telling me.