I mean Congress 100% gave him the power to do the only thing that's going to save us is that so many of the conservative justices are fans of the nondelegation doctrine.
No, Congress did not give him the power to implement arbitrary tariffs. They allowed limited power for emergency, targeted tariffs of limited duration and scope. This is so far beyond that they're clearly illegal, it's just a matter of whether the courts feel like writing another nonsensical opinion to allow them.
Yes, emergencies that he determines and they can if they choose to rescind. Just because you don't like it doesn't mean it's not exactly what powers they gave him.
My hope is the court rules that Congress cannot delegate all its power like it's been doing (nondelegation doctrine) but I'm not going to pretend he wasn't granted these powers.