os sequoia mac Battery overheating

Let it finish. That is part of the Sequoia update to offer more intelligent Siri Suggestions. You would not want to quit the process even if you could. There is quite a bit of processing your computer will be doing after the update including:

• Analyzing your Significant Locations for Map and Siri Suggestions
• Analyzing your Photos for Object Detection and for use with Siri to show those objects.
• If you use a Time Machine backup, that first backup could take an hour or longer.

All this is being done in the background and you can expect the Mac to run hotter as well as consume more battery power when not connected to an outlet. Some actions will also run slower until it finishes. Give it a couple of days.

Are you using the EOS Canon Webcam? The ewcService is used for the Canon Webcam. If so, you will need to check with Canon for an update. On their web page, they have this not:

MAC USERS: If you update your macOS to Sequoia then you will be unable to continue using this software without interruption. We are working on an update to enable camera connectivity with Sequoia and will let you know once the update is live. Thank you for your understanding and patience.

https://www.usa.canon.com/cameras/eos-webcam-utility?srsltid=AfmBOoqrdr_SSq4pYMWNBL3Hlb-Y5JEAp8jn4sWutiq8eM1v_V8Aiu4G

Check if there is a CPU intensive rogue process in Activity Monitor (View > All Processes) when the Mac should be idling.

My MacBook Air M2 also is really hot after the sequoia update, almost too hot to be on your lap! When I checked my activity monitor, this is what's using 200%... SiriSuggestionsSupport.framework/Versions/A/XPCServices/SiriSuggestionsInternalXPCServices.xpc/Contents/MacOS/SiriSuggestionsInternalXPCServices

It must be something useful because it won't let me quit it.

What to do?