Talk:Boss Strike/@comment-26516989-20130808000120/@comment-11460474-20130808001138

Trixie, try reading the original 3.0 patch notes for a better view. They added it so units won in rewards already come with a rank based on your own level. Level 51+ get the unit in r6 version, and levels before that get r5, then r4, the lower the level players are and so on. I bet there are significant stat changes between the ranks.