Trickster is poised to be one of the best ascendancies of 3.19, it might not have the best defenses or the best damage but it likely has the best total attack and defense bonuses of any ascendency in the game. Don't believe me? Here's what Trickster gives you:

One Step Ahead: 8% Action Speed (Along with freeze, chill and temp chain immunity)

Polymath: 30%+ More damage (10+ Masteries is easy to get) 10% Life, Mana and ES on kill, meaning you will never die in maps

Escape Artist: Allows for more ES while getting a lot of Evasion

Soul Drinker: With a 5 point investment and Divergent Energy Leech it gives you 42% ES Leech per second, which is all you'll ever need. Spellbreaker is way worse than Soul Drinker IMO, and it's not even close.

Edit: 34%, can spend 1 extra point to get 40% ES leech instead by dropping the 80% total recovery.

Example Builds:

Note these builds are generic on purpose and have two cluster jewel slots open with plenty of points left and have 10+ masteries. Feel free to optimize how you want, you can go to scion for more ES or to witch for more lightning damage and power charge support.

Claw Build (Howa Optionally):

https://pastebin.com/2WzcWk7G

Spell Build: (Uses Flask regen from mastery and chest to sustain Coruscating Elixir to go low life at the cost of a flask slot)

https://pastebin.com/qGaXUX9R