Kiting Movement Speed and empowered healing/sustain.
Empowered abilities and resource manipulation
Hitting an enemy champion with 3 attacks or separate abilities grants a burst of MS.
Hitting enemy champions with a spell grants maximum mana.
After reaching 250 mana, Manaflow Band restores 1% of your missing mana every 5 seconds.
Gain 10% CDR when you reach level 10. Excess CDR becomes AP or AD, Adaptive.
Gain increasing amounts of AD or AP, Adaptive over the course of the game.
+20 Ability Power or +12 Attack Damage, Adaptive
Recover health when you damage an enemy champion.
Heal for a percentage of damage dealt with your abilities. Increases with each unique takedown.
Cassiopeia massively benefits from the bonus Movement Speed on Phase Rush so she can chase down her target and continue spamming [E].
Manaflow Band synergizes well with Tear allowing you to use your abilities more liberally in the early game for trades.
The extra bit of CDR in the mid-game from Transcendence allows you to itemize into Magic Pen and raw AP for more damage.
Gathering Storm's scaling AP makes you an insane threat heading into the mid to late game.
Taste of Blood's lane sustain, when paired with the sustain of Cassiopeia's [E], allows you to trade pretty agressively without losing too much health.
Cassiopeia has massive ramping damage from [E] spam allows you to heal for a massive amount in an extended right/trade.