So I've managed to make the first few events be those which have the 25 extra fields, but how do I make all following events have these fields too, even with null value?
You need the filldown
command:
http://docs.splunk.com/Documentation/Splunk/6.6.2/SearchReference/Filldown
Did you try fillnull command? https://docs.splunk.com/Documentation/SplunkCloud/6.6.0/SearchReference/Fillnull
your current search | fillnull value="NULL"
OR just add a table command in the end to list all the field that you want to be listed even if no values exists
your current search | table ..list..of..all..fields..to..show