Class Design: Syphon Step 4, Venom Ideas (Patreon)

This one isn't a poll, but rather an open invitation for any patrons to suggest concepts for the Venoms the Syphon can use. To provide a brief overview; Venoms are special poison the Syphon can apply to their weapons that have powerful effects on struck targets. They're relatively limited use, starting with one prepared venom at level 2  and maxing out to 10 at level 20. The first venom that was created was a simple Deadly Venom, which deals a chunk of Poison damage to the target struck, with a Constitution saving throw for half damage. The options for Venoms are fairly limitless however, and I'd like to hear what my patrons would want to potentially see included in the list. I'd like to have a fairly wide selection, including venoms that might have a level prerequisite to create, allowing for even more powerful effects that are locked behind a level limit.