Mordekaiser and Shyvana
Long story short, I'm still fairly new to LoL and am trying to find champions that fit every role. So far I do a decent job with Ezreal ADC, Leona Support, and Shyvana Top, but my best character/role is Shyvana Jungle. I just lover her kit, since it fits my playstyle very well. Now, the only role I can't figure out is Mid. I don't know how to play it, every time I do I end up unintentionally feeding, but to add insult to injury, I can't find a champ that I like for Mid. Recently I saw someone wreck me with Mordekaiser, so I decided to look into him to figure out why his early game at least seemed so good. It turns out that it looks like a lot of his kit is similar to Shy's, with a basic-attack-enhancing Q, an AoE damage W, and an E that's great for poking and wave clearing. The ultimates are different, but I'm sure it can't be too hard to get used to one skill with some practice. So my question is: is Mordekaiser a good champ to pick up if I'm good with Shyvana? I don't plan on going into ranked matches any time soon, and really enjoy just spending time with friends. But I want to find a good mid laner, and want to know if Mordekaiser might suit my playstyle, since Shyvana does.

Syndra is probably one of the best champions for low elo mid laners. Her burst is stupid, she has few weaknesses other than being fairly immobile.
Too mechanically complicated. Has some rough counters. Stay away from him.
Oh my god I love Talon. He has a very specific playstyle, but he has some stupid burst and cleanup potential. In low elo/level, it's extremely easy to pick people off just by roaming. Unfortunately, Talon suffers from mana issues (low mana cost spells, but small mana pool), so generally start crystalline flask and farm/be safe until you can get your brutalizer or tiamat.
He has probably one of the cleanest power spikes in this list. Just make sure to know your limits when you go into Hammer Stance. Buy Tear first, then all ArPen and AD. Go nuts.
He's fairly demanding mechanically. If you're out of position with him, you might get cc-locked and punished for it. I probably wouldn't recommend him unless you've gotten used to his mechanics in custom/bots.
She's a little gimmicky mid. I'm used to her adc/top, but in certain matchups, she can dominate some melee mid champions and other champions who are weak early. Quinn's fairly easy to play, and she turns into an assassin late game with her double-Harrier combo and her AoE ult execute.