What are the rulings for the card named and designed by Kev Walker? List them in descending order of dates.
rulings refers to text; card named and designed by Kev Walker refers to artist = 'Kev Walker'; descending order of dates refers to MAX(date);
SELECT T2.text FROM cards AS T1 INNER JOIN rulings AS T2 ON T2.uuid = T1.uuid WHERE T1.artist = 'Kev Walker' ORDER BY T2.date DESC