Stalwart Defender enhancements

Tier One
Requires Toughness, Fighter Level 1

Tier Two
Requires Fighter Level 2, 5 APs spent in tree

Tier Three
Requires Fighter Level 3, 10 APs spent in tree

Tier Four
Requires Fighter Level 4, 20 APs spent in tree

Tier Five
Requires Fighter Level 5, Character Level 12, 30 APs spent in tree