Riven is currently one of the easiest comps to hard force and has great power spikes all around. Thanks to buffs to 8 Bit and Viego you now have much better secondary carries to help you win your fights.
The core concept is to run two 8 Bit with 3 Edgelords in early / mid game. You want to push for Level 7 in either Stage 3-5 if you're coming from a lose streak or in 4-1. Here you can field four 8-Bit with 3 Edgelords and 3 Pentakill, while you are slow rolling for Riven*3 (and Morde*3 if game allows it).
Once you have her you can push for Level 8, upgrade Viego and cap out your board with Kayn and 5 Edgelords. If you find an 8-Bit Emblem you can give it to Viego and aim for vertical 8 Bit and the big Prize cashout as your win condition.