Bjersgen (syndra) one shotting explanation?
Syndra was lvl 16 and kalista was lvl 15 They both had relatively the same amount of farm but syndra had 8/2/2 kda whereas kalista had 1/4/8
If we just look at their items 13,900g for syndra Kalista had 10,400g worth of items
Syndra build
(8 stacks)
Kalista build -

Kalista was first stunned and then W'd from 85/80 - 0%. Therefore no lifesteal for kalista as she wasn't AA. Just one W can kill with such difference? Notice that most of us complain about adc's 1-2 shotting with range but syndra did that with her W (range and aoe). I am pretty sure piglett (kalista) didn't expect that as well and was back at a safe distant. This is not healthy for the game if mages start one shotting from miles away ( I predominantly play mages).
Edit: Also if you notice piglet's reaction, he was certainly shocked. If a pro can get shocked then its not surprising that normal players get shocked too.
https://www.youtube.com/watch?v=dhICM3KkYwo
Death occurs at 39:11 exactly.