Blood finally has an official source port in the form of Blood: Fresh Supply released by Nightdive Studios.  If you're a fan of the game or just 90's fps in general, get on GOG or Steam and grab it.
Alongside Duke Nukem 3D and Shadow Warrior, it is one of the best Build Engine games ever produced and one of Monolith Software's finest hours.

https://www.gog.com/game/blood_fresh_supply