Combo-wise, the Breach lines this deck attempts are identical to those seen in cEDH, so Shadow should be just as relevant here
Despite this particular stipulation making Treasure Guardian, Protector of the Cave useless unless at a location, location cards are well worth putting in your deck - not just because they make this card a lot more viable but also because they grant you passive lore every turn, meaning you dont need to actively quest with them to get it, and cannot be targeted by direct damage unless the card being used indicates it can
Destroying a creature and having it die to lethal damage are two different things
And, if you deal noncombat damage (which shouldnt be difficult in red), you can pay two mana to bounce it back to your hand
There are many permanents that provide a steady flow of card draw in black, too
Double strike is one of the most powerful keywords in Neon Dynasty , so Lizard Blades will greatly benefit whatever it attaches itself to