This slow roll comp focuses on Katarina as the main carry and looks to 3 star as many units as possible. The comp slow rolls at level 6 for everyone except for Taric, and then goes to level 7 to add in Taric for a free Socialite buff.
Go for this comp if you find a good start with Assassins / Katarina and have solid items for Katarina.
Level up to 4 early if you want to start a win streak. Level up to 5 to try and continue the streak.
If you're weak in the early game, you can opt to save gold and lose streak instead.
At Round 2, level up to 6 regardless of your start. Put together the strongest team you can.
Once you hit 50 gold, look to start slow rolling for all of your units. The priority should be around Katarina, Talon, and Leona, but you can upgrade other units like Blitzcrank, Ekko, and Shaco as well.
Once you hit your 3 star units, level up to 7 and complete the comp.
Katarina items can be quite flexible. Some other strong items include things like Blue Buff, Rabadon's Deathcap, Hextech Gunblade, Titan's Resolve, Protector Emblem, etc.
Gain 2 Assassin Emblems.
Knife's Edge III
Your units that start combat in the first 2 rows gain 50 Attack Damage.
Gain a free Shop refresh each round.