I get the same electrical pulse as well , but it surges through my toes and it is so powerfuk that is is almost pleasurable , i cant help but clench my feet and writh aroung in my warm blanket , i still feel it days after taking LSD , crazy stuff <| sep |> Its usually used when its not possible to deal with the underlying cause . <| sep |> Generally I play it more situationally . Morello ' s gives cdr , mana passive , and of course the morello wound passive . This means Cass has more damage and sustained fighting , but no defensive stats early . Rylai ' s gives health , and the ability to kite , effectively making you harder to kill , and giving a lot of damage potential chaining your slows . However , when I rush Rylai ' s before Morello ' s I tend to run out of mana before the end of the fight . There isn ' t exactly a right answer . Faker tends to favor the tearsometimes negatronarmguardMorello ' s then situationally will build any of Rylai ' sthough this is almost always core , Seraph ' sonce tear is at 750 , Zhonya ' s , Abyssal , Dcap , Void , Liandry ' s , and sometimes Luden ' s . Though I ' ve certainly see him rush Rylai ' s , or Seraph ' s before Morello ' s . I only build Liandry ' s after I get Rylai ' s , and only if the enemy team is stacking health . Also note that the optimal page for Cass gives you 10 percent CDR at level 18 , meaning you cap with Morello ' sZhonya ' s or Abyssal . So generally you choose between one of the two depending on the enemy team .