Pros Built-in tanking ability in Eclipse. A lot of CC. Good initiator and ganker. Passive alone makes her valuable in team fights.

Cons Melee. Easy to ignore. Several skill shots. Solo lane might be problematic.

My setup is 9/21/0, but 0/21/9 and 0/9/21 are possible setups too.

The nine points in the Offensive Mastery Tree is obviously for Archaic Knowledge . The 15% MPen makes her abilities pack a bit more punch, making her harder to ignore. This helps divert attention away from your squishies somewhat, which is what you want to do as a tank.

In contrast, if I spend nine points in the Utility Mastery Tree, I benefit from Haste and one point in Utility Mastery . However, Leona isn't terribly reliant on buffs, and I feel the benefit of Archaic Knowledge to outweigh Haste .

The points in the Defensive Mastery Tree should be fairly self-explanatory.

• Greater Mark of Magic Penetration: These will help you dish out the damage early game with your skills for better harassment.
• Greater Seal of Armor: These will help you tank the damage early game so you can have an easier time harassing and farming.
• Greater Glyph of Scaling Magic Resist: Early on, the harassment mostly comes from auto-attacks rather than abilities, while the inverse is true as the game progresses, hence the MRes/level runes.
• Greater Quintessence of Health: These will help you tank the damage early game so you can have an easier time harassing and farming.