Preamble
Kane's value around the league right now is completely subjective... some teams likely wouldn't want him under any circumstances, whereas others may be willing to put up with his off-ice antics so long as he produces during games. Given their Cup aspirations, need at LW, and Kerfoot's expendable contract, Toronto seems like one of the teams that should be willing to gamble on Kane. So, what would a trade look like built around Kerfoot for Kane with 50% retention? Here's my attempt...
The Trade
To Toronto: Kane (50% retained)
To San Jose: 2022 1st, Kerfoot, plus some B level prospects if there are any in Toronto's system that San Jose want included
Toronto get a huge upgrade at LW on one of their top 2 lines without taking on additional salary
San Jose get a 2022 1st for essentially paying Kerfoot 7 million each of the next 2 seasons to replace Kane in their lineup, and then having 3.5 million in dead cap space in 2025 and 2026. They also get a couple of B level prospects if there are any in Toronto's system they really like