Which one should I buy? They both seem pretty fun, but I haven't played much of either. I'm waiting for them to go on free week and sale. Which one is funner, which more viable, which stronger? What else should I know?
I really like both Rengar and Lissandra. They each have their own clear cut weaknesses and strengths. Honestly, it depends on what you want them for.
Are you getting them to play in Solo Queue or in a Team match? If Solo, use Rengar; if Team, use Lissandra.
Do you plan on going jungle? If yes, play Rengar.
Do you plan on going top? If yes, you can use either. Both have great escape and lane dominance.
Do you plan on going mid? If yes, play Lissandra.
Do you plan on going bot? If yes, do not think about either of these champions.
If I had to say, I think Rengar is a little more "in" right now with the whole mobile meta. Go with him.
