GC Titles

Hi, this is the first time I've pushed to gc in 2v2 and I'm also pushing gc on all extra modes for the titles but I dont understand some things: -If i got the gc rewards winning 10 matches at gc level in 2v2 (so I already secured the gc rewards and gc title), I have to win 10 matches for every other mode I want to get the gc title or just one is enough? -If just one is enough the rankup from c3 to gc1 will already give me the title or I have to win one match starting already at gc1? -And If I do all this I truly secured the rewards and all the titles or if I rank down before the end of the season I wont get them? Thank you if you could answer these questions