The atlas bear would win.
polar bear
a lion mostly
It depends on who is bigger. If the black bear happened to kill the lion, the black bear would get badly injured.
The grizzly bear would probably win
African Lion
The giant black bear would win, but it would be injured.
Neither as the black bear is from North America and the lion from Africa and Asia. They never meet in nature.
That would depend on the species of bear. For instance, a lion could more than likely defeat a black bear, but a grizzly bear would be a far more dangerous opponent.
a polerbear would win because it is stronger and has stronger and sharper teeth and the lion will be helpless
A tiger, as they are bigger and they can take down a brown bear, whilst a lion is smaller and can't kill a brown bear.
A lot of people will say lion , however they are wrong because they are just stupid lion fans that know nothing about a tiger's advantages. The tiger will win because it is stronger! heavier, more agile, bigger, has longer canines, is a better fighter, is smarter, and is not lazy and waits for females to hunt. Tigers rule and lions suck
In power, most likely bear, to win a fight, the lion, speed and almost as strong/stronger than the bear.