The second link (I know the first story already, and you don't describe it accurately) notes, "Soros has argued that hedge funds did not start the crisis it was, in fact, the reaction of Thailand's central bank to the
knowledge of hedge fund positioning that exacerbated the problems." And also that all he did was take the correct side of the bet (not the biggest hedge-fund investor doing that). Your claim is that he boasted about being the primary cause of a financial crash! That's quite a difference. Doesn't inspire confidence here.
The third link says: "Concerns over currency devaluation and worries the country may default on its loans have plagued the Russian market for weeks.
Those fears hit a fever pitch Thursday after billionaire financier and philanthropist George Soros urged Russian economic leaders to devalue the ruble and introduce a currency pegged to the dollar or euro.
In a letter published in the British newspaper
Financial Times, Soros said the exchange rate should be 15 percent to 20 percent below the current rate to reflect the recent oil price collapse.
Soros, an influential voice in the financial markets, hit it big speculating against sterling and other European currencies in 1992.
As of October, Soros Fund Management, the principal investment adviser to the Quantum Group of Funds, had invested more than $2.5 billion in Russian business, making Soros the leading Western investor in that country." Again, not the slightest bit of support for your claim.
And see Quipling's post.
If you modify the claim to the more-accurate: "He's made good investments and people on the other side of them might be mad," it doesn't sound like a likely motivation for the attempt, especially in comparison to the demonization from the right (that he's essentially behind all left-wing anger at bad governance).