For most readers, the answer lies in balance
The first is a triggered ability: "When this permanent enters the battlefield, target player may search their library for a card named [name], reveal it, put it into their hand, then shuffle their library." (7/5/2024) Note that the target player searches their library (which may be affected by effects such as that of Stranglehold) and that the card they find is revealed, even though these words aren't included in the ability's reminder text
The results I obtained turned out to be correct - see post above for link to image of uncut sheets
Next up, Niv-Mizzet, Parun
As the replicate triggered ability resolves, you'll copy Siege of Towers for each time you paid its replicate cost, even if the original spell is no longer on the stack at that time (perhaps because it was countered)
Vivi fuels your board with endless value, turning every spell into a spark of chaos and firepower