There're a lots of version of skill build but i think this one is the best :)
- Glacial Spike/Poison Missile – Glacial Spike is maxed while Poison Missile is almost maxed. As you can see from the build, it is pretty much a pure-ice build. While Poison Missile is an incredibly good skill, being an ice-type attacker, Glacial Spike also does significantly good damage with good AOE and low cooldown. It also has a chance to freeze a target.
- Shock Wave – More of a defensive than a DPS skill, that pushes enemies away from you. I guess an Elestra has the best possible crowd control abilities with all the slows and freezing, this skill may seem optional.
- Mana Flow - Max at Lv1. No need SP to learn. A party buff that reduces MP consumption by 20%.
- Aerial Evasion - Lv3. Good for regain position after you are floated in the air.
- Physical Mastery - Lv3. Hp is always good. Not maxed due to SP constraint.
- Blink - Max at Lv5. Shortest cd is required. Eraser, Triple Orbs, Gravity Ascension and Gravity Switch can be cancelled half way during casting by blinking. This improves the flexibility of the these skills tremendously.
- Escape - Max at Lv5.
- Mental Mastery - Lv1. Increase Max MP.
- Counter Spell – Similar speculation as Shock Wave. Due to good crowd control abilities, this skill may seem optional.
- Mental Training – I believe the remaining SPs should be invested here, or at least at Lv1. Having various skills pumped high, MP consumption is definitely an issue for the player.
- Frost Wind – You may be wondering why this skill is maxed. This skill may not be a DPS skill, but it has superb slowing abilities (and probably greater AOE). Mainly for PvP usage. PvE conscious players may just put this at Lv1.
- Glacial Wave – When levelled high, it has higher freezing duration. During PvP, if this skill is levelled high, you will be able to chain 1 or 2 more skills upon freezing your enemies successfully without them escaping the ice trap. However, if your opponent has extreme high water/ice element resistance, your freezing duration will drop draatically.
- Icy Fraction – Since this build is so focused on Ice, Icy Fraction is maxed so the sudden damage outburst would be tremendous.
- Ice Shield – Pre-requisite would do since Elestra has another Ice Barrier defensive skill.