I had almost forgot about orbitals applying on hit effects so they do scale with vampire, but to be honest I haven’t actually those on hit effects work with ice, static, and lava (I’ve used orbit quite a lot so maybe a glitch?). I still believe its a great card overall throughout the game, the point i was trying to make was that you just cant over rely on it. And you dont really need that much bullet speed for orbital to be OP, you can focus on adding orbs or just adding orbital damage and that works just as fine if not better (by the time you get max bullet speed its already late game and most things can tank that). By endless turtles i think you mean purple right? well at least in my experience if your already having a hard time killing the turtles that only makes assassin better as it kills them under a certain point (also for me it seem to bypass their armor for regular-red turtles). I will admit at max armor shredder does get rid of the armor but thats at max. of course its gonna be OP late game, the problem is that it takes a ridiculous amount of upgrades to get to that point and said upgrades are invaluable early-mid game. If you focus on armor shredding it will kill you early-mid game and i cant think of another card (besides maybe blue flame/crit?) that does that. Assassin on the other hand is good mid game, easy to upgrade, and also becomes OP late game. Once fully upgraded it becomes so OP that armor shredder is just obsolete. Since you are favoring late game in your comment; Armor shredder at least takes 1 shot to take off the armor of turtles and then you can attack. Meanwhile assassin can attack from the get go and insta-kills below half health. Although if your claim about it working with electric is true (I haven’t heard of that) then that might change things a bit late-game but early-mid game is a different story. It’s not hard to see which is the better card overall. Of course max Armor shredder with electric is better but there is no way you’re upgrading armor shredder to max and electric enough in a regular game without dying (which makes it only viable in endless mode). This is supposed to be a guide for beating the game not really for endless mode as you can just grab every upgrade at that point making a guide useless in the first place.
TL:DR Armor is still worse, orbit is still op