League of Legends (LoL) Question: cassiopeia at bot lane

First of all, you need to understand that "ADC" stands for attack damage carry. This means it's a carry that focuses on building Attack Damage rather than AP.

Secondly, Cassiopeia's current thematics involve her ramping up in power through farming and harass. Botlane has a lot of activity due to supports being constantly on the run for starting or stopping engages from the other side while helping their carry farm safely or give him kills. Because Cassiopeia has a very mediocre early game, you don't want to place her in a place where she will have to worry about two extra people (the supports).

Thirdly, midlane is a short lane, guaranteedly close to blue buff - which Cassiopeia adores - and a place where she can ramp up on experience, since levels also greatly empower your Ability Power Carry's game: midlaners should always be 1-2 levels ahead of the rest of the team up until everyone is level 18, givem them much needed extra power before levels stabilize.

If you desire to take an AP (ability power) carry botlane instead of an AD carry, consider champions that have a strong early game, farm well, have CC (stuns/slows/etc) and a good power spike at level 6 (Ahri, Syndra, ziggs, maybe Azir, or a duo of utility + damage supports like lulu, morgana, karma, zyra and vel'koz). However, again I recommend the mages midlane (and some toplane) to ramp up in levels while your attack damage carry has his farm protected by a support.

Pre-nerf i would say sure and i've seen people do it. I remember someone who regularly did Cassiopeia + Soraka bot lane and got to gold doing it. It even worked in plat level games.

I don't know how it would work now that cass got changed a lot. You would have to try it and see, and of course Soraka won't work because lack of mana sustain now (screw you rito, the one time it was useful). But other supports work.

rush Will Of The Ancients > GG :)

even if you are currently at low levels, ur aim is certainly to improve i suppose... At lower levels you can try everything for fun, but at high elo, a team will not function without an adc at bot lane, its a rule of thumb.. however, i played once with a cassiopeia supp, she was quiet helpful past lvl 6, but she gives no sustain for the adc, will definitely help you farm though... If you like cassiopeia that much, main her at mid lane, this will help you later :)