The caveat to this is with the daybound and nightbound mechanic from Midnight Hunt, where cards enter as the appropriate side based on whether its currently Day or Night
I think Dormant Sliver is awesome because you could, in theory, side it in against Sliver decks, play it and laugh maniacally as their tribal synergies amount to nothing because their Slivers cant attack because all Slivers have defender
(2025-06-06) "Shield" is not an ability that creatures have and shield counters are not keyword counters
The reality is, if you want to just get three permanents onto the battlefield for a flashy finish, you don't have to spend 7 mana to do it
If the target opponent is an illegal target as Susurian Voidborn's first ability tries to resolve, it won't resolve and none of its effects will happen
A solid recommendation is to toss at least one counter on Siege Veteran itself to help it dodge at least some removal, like Cut Down