PROS


+ High burst dmg
+ lots of gap closers
+ Got invisibility (and can spam it)
+ Aoe ult with stun
+ is a new champion (meaning some people do not know how to react)
+ fun to play
+ Strong LvL 3 all in

CONS


- Hard to master
- Weak to CC (squishy)
- can be hard to manage mana costs early
- Falls off when fighting tanks
- Cant do much before LvL 3
- Stronger around the jungle and falls off near enemy or ally base (bcz no element and no walls)

Passive - Every first ability or auto attack on enemy deals bonus physical Dmg every few seconds, after changing element the CD resets instantly, you dont even have to hit the target with the second element( once you pick different element it will reset).

Q - without an element it is useless and i use it only to secure minions at lvl 1.

brush Q - Great to spam proc , engage and escape tool in team fight, brush q can be spammed for a long during when you have low cooldown on W (u can use w to collect another brush while inside a Q brush, great tool to deal with Auto attack based champion, during end game the best way to land a good ult is using it to sneak into the enemy team.

water Q - with 0.5 sec root.

earth Q - only for targets with less then 50% hp otherwise its a filler to change an element

W - first it can be used as a dash to dodge skill shots or jump over walls or as a gap closer, i think you should always keep an element until your W Cooldown is off then you can use the element and collect a new one instantly or until you can secure a kill or save your teammate,
having an element not only gives you bonus dmg and attack speed it also gives attack range, dont throw your element so quickly if the target got high hp bcz you can get a few AAs and then finish it with q once it dashed away or flashed.

E - just like yasuo's dashes only it has long cd and is a bit farther i think, it applies the element you possess with the passive, engage tool and dodge tool and escape tool, it can be combined with q to cancel its animation and to auto aim on the target that q, it can be combined with w to cancel its animation, and it can be combined with the ult to auto aim the target.

R - HUGE aoe stun dmg and knock back, its much stronger in the the jungle or the river bcz there are allot of walls and a river..., great baron and dragon steal tool , great to burst down squishys. this ability can absolutely win teamfights, use brush Q or flash to sneak a good ult on the enemy.