Possible Clues:

• Maker of better laws - and anagrams!
• Concerned with first of two articles for Luther?
• One making changes (in practices)
• Person who advocates change
• It's not about the latter, for a change
• One making improving changes
• One who changes or improves, say, an organisation
• One who changes organisation in order to improve
• Person who advocates change again late
• ... sometime after King Edward backed Wycliffe, say