New MapleStory - MapleSea Adventurer Event Rings?

Lirin's Ring and the 3 new rings... which one is better?

Explorer's Cruel Ring
Ring - All classes
Required Level: 30
Weapon Attack: +3
Magic Attack: +1
HP: +180
MP: +100
One-of-a-kind
Cannot resell to merchants

Skill:
Level 30
Skill Gained - Instant Death
Level 1

Critical:
Level 30
Probability - 5%
Damage - 20%

Explorer's Critical Ring
Ring - All classes
Required Level: 30
Weapon Attack: +2
Magic Attack: +1
HP: +180
MP: +100
One-of-a-kind
Cannot resell to merchants

Skill:
Level 30
Skill Gained - Instant Death
Level 1

Critical:
Level 30
Probability - 10%
Damage - 10%

Explorer's Magical Ring
Ring - All classes
Required Level: 30
Weapon Attack: +1
Magic Attack: +5
HP: +100
MP: +180
One-of-a-kind
Cannot resell to merchants

Skill:
Level 30
Skill Gained - Knock Down
Level 2

Critical:
Level 30
Probability - 5%
Damage - 20%