Escaping T-SQL Keywords

If you want to use reserved words as table or column names, you have 2 options:

use brackets (the SQL-Server's way): SELECT [Kill]

or double-quotes^* (the ANSI/ISO standard): SELECT "Kill"

Your whole statement would become:

SELECT [serial], [Kill] 
FROM tbl_pvporderview 
WHERE [Kill] > (?) 
ORDER BY [Kill] DESC ;

^{*: Of course, using double quotes (SELECT "Kill") would necessitate that QUOTED_IDENTIFIER is ON. You may encounter databases that the setting is still SET OFF.}

Wrap the column name in square brackets:

$sql = "SELECT [Kill] FROM tbl_pvporderview";