It's not often I see a new spin on a Cursed Founding chapter's "flaw", but I really do like this one!
The idea of being blind and relying on bionics and their superior senses is a fun one, do they echo-locate to help with sight too (yes, there are regular humans who can do this today) if they are conducting void combat etc?
Now on the Warp Sight front, if you wanted to add that extra dollop of grim dark and add further to the horrors of the 21st Founding's ill fated brethren, you could make it that the development of the Warp Sight eventually drives the Imperial Consul mad as they are borne witness to the Warp's power and entropy. Only those who are supremely highly disciplined can survive for more than a Century etc. As a result most Astartes when they reach this level of affliction, voluntarily choose to go out with an honourable bang in combat, very much akin to the Death Companies of the Blood Angels?
I think super senses would fail in void because there is no sound in a vacuum. But your take on Warp Sight is... AWESOME! Oh man, I really like it. I might use it with my First Company Veterans. Maybe the Vanguard Veterans are seeking their doom in battle?
Edited by Sugarlessllama, 02 February 2020 - 09:16 AM.