As a startup player, every runner should be aware of Saisentan. It has the honor of being the only card in Startup that, with no setup, can flatline an unsuspecting runner with 5 cards in grip. Yes you need to have at least 3 of a card type in hand to make that possible, but that's not really that unlikely, especially if you're running a specialty runner like Az McCaffrey: Mechanical Prodigy or Ken "Express" Tenma: Disappeared Clone. But what are the odds of being flatlined? If you were curious like me, the math is: Assuming the corp picks the 'correct' card type: 3 Same type in hand - 10% chance of being flatlined 4 Same type in hand - 40% chance of being flatlined 5 Same type in hand - 100% chance....
Seeing the above math, and the fact that the minimum is 3 net damage, and you're often worried about being low on cards against Jinteki, it's clear this ice is meant to be a punishment for runners face checking random ice with no breakers, or basically an ETR against runners who don't have a killer installed (just, this ice ETR by killing the runner. Which will do it). You can even cheekily get some damage on runners who think they are safe putting a Botulus or Boomerang on this and running.
So how does Saisentan do when the runner has the killer? In startup, it's okay. Basically every killer is breaking for 3 creds. Bukhgalter gets through with 4 but their rebate brings to 2, and Afterimage also spends 2. Odore pays 5 if they don't have their virtual friends, and Echelon has to pay 6 if it's by itself. None of these are terrible deals, but really you're looking for an unprepared runner facechecking this. And that's why runner friends, always be aware of your face.
<B>Saisentan significantly affects runner calculations on how dangerous an unrezzed ice could be</b>. If they get surprised by Saisentan and don't have a method to break most of its subroutines, they will probably lose or at least take a devastating amount of net damage. <Br><Br>If the runner knows/suspects your deck has Saisentan, all of your unrezzed ice look scary early on, enabling high-value early plays. <b>This ability to act boldly early makes Saisentan very valuable.</b> It fights very well against most of the cards a runner might use to break an unknown ice early (e.g. Boomerang, Engolo, and Botulus), so a turn 1 Rashida will probably work out for you even if they do think they have a way inside. It's also the perfect rez cost (5) to deter early Diversion of Funds plays if you have an unrezzed ice on HQ. <br><Br>After the runner has a killer, it usually costs 3 to break Saisentan, which is reasonable for a 5 cost ice. MKUltra costs 6 to fully break Saisentan, which is excellent ice efficiency.— superheronation