IPA: /ˈwɪtʃˌsoʊvər/
KK: /ˈhwɪtʃˌsoʊvər/
A word used to refer to any one or more items from a group, without specifying which one.
You can choose whichsoever option you prefer.
Whichsoever is formed from "which" (from Old English "hwilc", meaning what one or what kind) and "soever" (from Old English "swa" meaning so or in any way). The word "whichsoever" means any one or any kind of the specified options.
Think of 'which' as asking about a specific kind and 'soever' as meaning in any way — together, they help you remember that 'whichsoever' refers to any one of the specified choices.