By Phil Black, Faith Karimi and Victoria Butenko
KIEV, Ukraine (CNN) -- A tidal wave of change has washed over Ukraine, sweeping away its president, setting free a prominent opposition leader and leaving an altered political landscape.
Saturday was a day of dizzying developments. Sunday brings a host of questions: Where's ousted President Viktor Yanukovych? Who's in charge? And most important, with the Sochi Winter Olympics ending, how will Russia -- Yanukovych's ally -- respond?
Here's where things stand:
Will a return to the old constitution appease protesters?
The series of concessions started Friday with Parliament overwhelmingly approving the return of the nation's 2004 constitution. Reinstating it gives the President less power -- a key demand of protesters who'd taken over Kiev City Hall for weeks -- and paves the way for lawmakers to appoint key ministers.
A few days before the vote, the opposition had sought to introduce amendments in parliament that would have limited the President's powers, but the speaker of Parliament refused to allow it. Bloody clashes followed.
With the old constitution now getting the green light, will protesters who'd taken to the streets for weeks feel that their goals have been met?
The ex-prime minister is free. Will she become the opposition leader?
Just like everything else in Ukraine, there are no clear answers.
Former Prime Minister Yulia Tymoshenko was freed after 2½ years in prison and returned to the capital Saturday.
And she had strong words for the President.
"Today, Ukraine has finished with this terrible dictator," Tymoshenko told a cheering crowd at Kiev's Independence Square, the scene of deadly demonstrations.
She served as prime minister from 2007 until she was forced out of office in 2010 after losing the election to Yanukovych.
A year later, she was sentenced to seven years in prison after being convicted of abuse of authority over a natural gas deal negotiated with Russia.
The West considers her case politically motivated and has called her "a political prisoner."
She is considered a hero of a 2004 revolution that forced the results of a presidential election won by Yanukovych to be thrown out.
Who's in control until May elections?
The Parliament's voted to oust the President and hold new elections on May 25. It also appointed Oleksandr Turchinov, the speaker, to take on Yanukovych's duties until then.
Lawmakers also fired several ministers, including the foreign and education chiefs.
Yanukovych, however, insists that he's still in power, and the opposition coalition is a chaotic mix of voices, each working to assert dominance.
Former world champion boxer Vitali Klitschko has been the most well-known opposition figure during the crisis. He heads the Ukrainian Democratic Alliance for Reforms party. But the opposition bloc goes well beyond Klitschko and his party.
Then there's Arseniy Yatsenyuk, another opposition figure and former foreign minister.
Last month, the President offered a package of concessions under which Yatsenyuk would have become the prime minister and Klitschko deputy prime minister on humanitarian issues. The opposition refused.
The President's missing. Where is he?
Last we heard, Yanukovych was in Kharkiv, a pro-Russian stronghold near Ukraine's border with that nation.
He tried to leave the country by plane but was turned away, authorities said.
The country's acting interior minister said Sunday that government officials in Kiev don't know the whereabouts of Yanukovych and two of his top ministers.
On Saturday, the President and his entourage attempted to board a charter flight without proper documentation in the eastern city of Donetsk, according to the head of Ukraine's Border Guard Service, Sergei Astakov.
He was on the tarmac when he was turned back by security forces, Astakov said.
But the President took to television airwaves, saying he's still the legitimate leader. He said he was forced to leave Kiev because of "vandalism, crime and a coup."
"I don't plan to leave the country. I don't plan to resign. I am the legitimate President," he said from Kharkiv.
How will Russia respond?
Close ally Russia has been busy hosting the Winter Olympics, which end Sunday.
But it's closely linked to the crisis, which started in November, when Yanukovych scrapped a European Union trade deal and turned toward Russia.
Russia offered to lend money to Ukraine in a deal worth billions of dollars and lower its gas prices.
The deal sent protesters to the streets as Russia pressured Yanukovych to crack down on demonstrators.
On Saturday, Russia's ambassador to the United Nations, Vitaly Churkin, condemned what he called Western attempts to influence the outcome of the tumult in Ukraine.
"Either they don't understand the consequences of what they're doing, or they're engaged in a very provocative game of destabilizing Ukraine and therefore Eastern Europe," Churkin said in a post on his official Twitter account.
Churkin has accused the opposition of wanting to take power by force.
"If those so-called democratic opposition leaders come to power on the shoulders of thugs, that will not produce democracy in Ukraine," he said.
CNN's Victoria Butenko, Phil Black and Ingrid Formanek reported from Kiev, and Faith Karimi reported and wrote from Atlanta.
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