League of Legends (LoL) Question: Vel'Koz vs. Taliyah

The main differences between Vel´koz and Taliyah are the game vision and the skill, Taliyah needs more of both of them due to her W > E combo and her ult which is a nice tool to engage, gank/help your teammates but if you don´t know in what point of the game do this you can regret it (if your enemie is smart and you didn´t push before roam with your ult they will probably take your tower). And Vel´Koz E it´s too hard to hit but you don´t really need that to do tons of damage. Whatever, this meta is a bit hard for Vel´Koz because the gap closer-assasin- crowd control mages are the most popular and his hard counters because his lack of mobility, but AP supports are OP in low elo and VelKoz, Zyra and Brand are very solid choices there.

Summarizing, VelKoz is better for lowelo but if you want to learn something different, more into the meta and with some hidden potential, learn Taliyah. Hope I could answer your question! ^^

I am not a midlaner so i will suggest other thing,

If you want them you can just buy in the store under the accessories, the Hextech Mystery Champion shard, it will give you an champion shard that you can make into blue essence, this can be a cheaper way to get new champions.