He cleverly gets rid of Shishupal, making him exhuast the “100 mistakes I spare his life” promise he had given to the latter’s mother. And earlier he had eloped with Rukmini who was betrothed to Shishupal, but had her heart on Krishna.
Engineered killing of Drona. He knew no one can kill Drona as long as he holds a weapon, and only way to make him drop it is to emotionally break him down by telling that his son died. There is no way anyone would disbelieve Yudhishtira as he is the “king of dharma”. So Krishna named an elephant as “ashwtthama” (name of Drona’s son) and asked Bhima to kill it, and then asked Yudhishthira to shout “Ashwatthama, the elephant is dead..” but “the elephant” part of the sentence in a low voice. So Drona, who was at a distance could hear only “Ashwatthama is dead“. As expected, Drona dropped weapons heart broken and Pandavas killed him with ease. (So technically, Yudhishthira the “king of dharma” didn’t lie. Hmmm..)
Engineered killing of Jarasandha: Here is the story from wiki
Bheema did not know how to defeat Jarasandha. Since, Jarasandha was brought to life when the two lifeless halves joined together, conversely, he can be killed only when these his body was torn into two halves and find a way as how these two don’t merge. Krishna took a stick, he broke it into two and threw them in both directions. Bheema got the hint. He tore Jarasandha’s body into two and threw the pieces in two directions. But, these two pieces came together and Jarasandha was able to attack Bheema again. Bheema got tired after several such futile attempts. He again sought the help of Krishna. This time, Lord Krishna took a stick, broke it into two and threw the left piece on right side and the right piece on the left side. Bheema precisely followed the same. Now, he tore Jarasandha’s body into two and threw them in opposite directions. Thus, Jarasandha was killed as the two pieces could not merge into one.
He took Pandavas away the night Ashwatthama destroyed Pandava camp after they won the war. He knew it was going to happen. Ashwatthama, with KalBhairav entered into his body, burned the Pandava camp into ashes killing every single person.. But Krishna saved just the Pandavas & Draupati.. Why didn’t he save others? No idea! Might be that he wanted to do a balancing act.
Some more stories of Shri Krishna in short:
She disguised herself as an angelic woman and offered Yashoda a brief respite by volunteering to nurse baby Krishna (with her poisonous milk). Can we say Krishna “sucked the life out of her?”
the Tornado Demon! Trinavarta is probably the most unique rakshasa-form – ruthlessly sabatoging everything in his path. He whisked Krishna off his feet…but Krishna blew him (and his pride) away.
Bakasura – the Crane Demon – simply got greedy. Lured by Kamsa’s promises of rich and swanky rewards, Bakasura “tricked” Krishna to come close – only to betray the boy by swallowing him. Krishna forced his way out of course and put an end to him.
This giant Serpent Demon slithered his way to the outskirts of Gokul, opened his mouth wide and had all the kids squealing in delight by thinking they had discovered a brand new “cave.” They all hopped inside – only to be trapped. Some versions of the story explain Aghasura to have once been a handsome king who was cursed by a crippled sage for laughing at the poor man’s disability.
This Donkey Demon was a real pain-in-the-Ass. Even Mother Earth trembled under Dhenukasura’s stampede. This was a true joint venture between Balaram and Krishna – with Balaram taking the credit for the final blow.
A true bull-y in every sense of the word. Aristasur the Bull Demon stormed into town and challenged Krishna to a bull fight that all the heavens watched.
Another story of deception: Vatsasura disguised himself as a Calf, mixed himself into Krishna’s herd and tricked him into a duel.
This Horse Demon was apparently mourning the loss of so many of his fellow rakshasa friends, so he approached Kamsa to sponsor his battle against Krishna.
Image credit to the original Uploader
Short stories credit : Gnaana.com