Sorry to see the Arena dying, I guess it's unavoidable, I don't have the time to help with that. But I still try to post a new platinum deck every time the old one reaches 1 HP, it'll never be a mono deck, it'll always be something different, though usually with only a few different cards to make it easy to balance. The idea isn't to reach the top position, certainly not to make money, I have way more than enough (though I'll never reach level 80, it seems), but to give others something at least semi-interesting to play against. Anyway, with less and less competition reaching the top position has become easier and I've just managed it for the second time, the first time was maybe a year ago and here are the two decks which managed it. Both with me at level 77:
The first one was a bit of a surprise, since I imagine a lot of people are still using PDials, which easily defeats that deck. My new one has a combo I haven't tried before, making those damn immortals and their shards even more powerful by throwing in a few shards of patience. I like adding silence to a deck, that's usually a nasty surprise for players.
