Maining Ahri is a good decision. Ahri is amazing in 1vs1 situations and she's very usefull in teamfights especially with rylai's crystal scepter or glacial augment. This champion is able to dash in, get a kill and dash out. Ahri ain't only good as a midlaner, but she's also a good support. With her charm and damage she may carry the adc and help getting him fed.

pros:

-Ahri is a flexible pick.

-Amazing in 1vs1 against non-tanks.

-Hitting charm may result with one shot.

-The q return is true damage.

-The mobility of Ahri is amazing, this champion is easily able to dash into a teamfight, get a kill and dash away.

-This champion is easy to learn

-Good and easy roams[/color]

cons:

-Ahri is skill shot reliant, if you miss your charm you may lose a fight/teamfight.

-Ahri is squishy

-Long cooldowns without cdr.

While playing ahri, make sure you remember to roam alot after pushing your wave. Roaming is good not only because it can help your team, but also because it can get you ahead of your enemy laner.

For some people using glacial augment or buying rylai's crystal scepter may seem like a troll build for normals, but it's actually quite effective on rankeds. It's good because ahri's q can hit multiple targets making enemies easier to leash or chase.

Playing vs ahri is simple, you either dodge e and kill or get charmed and die. The best pick vs ahri for me are camille, katarina and aurelion sol, but pick whatever you are confident with (as long as ahri doesnt counter the champ you want to pick).

Ahri is a good firstpick. In theory ahri has some counters, but all of them are winnable.

Ahri on supp and toplane may sound troll, but is actually quite effective. The only situation in which picking ahri top/supp is troll is when your team needs a tank.

The best way to improve is playing normals and watching streamers like faker or pekinwoof. Even if the streamers you watch don't play ahri, you gain more knowlage about the game from watching high elo streamers. Knowing how to play your champ isn't enough to be good at it. You also need general knowlage of how to play league of legends, that's why pro players can play almost anything on the lane they main.

Seraphine may be the hardest matchup for ahri, but its winnable. First of all, remember to always take cleanse vs seraphine. Second of all, don't try to 1vs1 her after level 6. Play for your team by roaming and helping with objectives.

While electrocute is easier to use and deals more damage, you can use it on one target only, while dark harvest's cooldown is reduced to 1.5 seconds after takedown. You stil may rather electrocute for easier early or glacial augment to make teamfights easier for your m8s, but imo dark harvest is the best rune for Arhi.