The Snek has completely won me over and eaten into my S-Billy savings. I wasn't going to pull her W-Engine but I folded on that too and have gone from around 30k score to almost 40k in this Shiyu rotation.
I don't have the best teammates for her but this Qingyi team is insanely fun to play and surprisingly effective here.
I've seen a few people mentioning how Anton Sig is already 90-92% damage output compared to Cissia's Sig, even when talking about her in a hypercarry scenario. I want to point out that these calcs are based on team damage in a Seed+Cissia scenario where Cissia is only ~30% of the team's damage with Seed making up the bulk of it.
Cissia's Sig only buffs her own damage output, not the team's. When Cissia is suddenly responsible for 90%+ of the team damage, that "-10%" damage difference is suddenly looking closer to -30% difference.
The same can be said for her Mindscapes too which I've seen people complaining about. Her mindscape 1 buffs the whole team plus her own Electric Res ignore so the 15-20% calcs will be be a solid amount better in a solo carry team.
Her Mindscape 2 however is purely personal damage (More venom and +35% damage on hold basic) and already calcs at around 10-15% team damage increase over M1 in Seed teams. Since this will more or less triple as a hypercarry, her M2 when solo is one of the biggest M2s in the game.