Unfortunately, death is permanent in Riverview, in a general sense. There's a little more information here, but to save a click, because of the tech and magic available in Riverview, characters who die technically can be revived for a maximum of 2-3 hours, depending on their circumstances and injury or illness. After that length of time, there would likely be permanent physiological damage, either mental or physical. If you are interested in that kind of side effect, we can definitely talk about it, or Tony could simply be rescued within the 2-3 hour window after his death.

Alternately, I am completely fine with you plotting out a resurrection by a fellow character, such as what was mentioned in the comment about Misty!

Just let me know what you'd like to do.