On the Nature of Rudy Holiday's Chronic Illness
So â what do we know about Rudy's illness, aside from the implication that it's terminal?
The symptoms we know of so far are:
The incurable cough of death â more specifically, a very frequent, productive-sounding cough. This could indicate a lotta things, but means that Rudy's lungs are probably involved
Chronic fatigue â if Rudy pushes himself beyond his limits, he's gonna feel really sick. He attends church, but has to return to hospital immediately after. Talking to friends and family is a form of exertion. Conspicuously absent from this is any implication that Rudy's balance or mobility is affected â otherwise, he probably wouldn't be able to have stayed on the ladder for as long throughout the Festival as he did.
In chapter 1, Rudy dismisses Kris' questions about his conditions by saying he's there for tests. While this is clearly writing off a very obvious issue, it's possible that Rudy's condition requires ongoing monitoring. Notably, we never see any kind of IV in Rudy's room â this implies he's not receiving any IV pain medication, nor having his levels constantly monitored. One could interpret this as him requiring follow-up tests, but not being expected to die or grow worse soon. This could mean that Rudy's illness has existed for some time, but has only recently progressed to this point.
Rudy tells Kris that he feels an obligation to recover for Noelle's sake. While this could be Rudy covering up the fact that he's dying, this seems unlikely given Rudy's nature as the responsible but nice parent of the Holiday family. That is, it seems out-of-character for him to set up entirely unrealistic expectations of recovery to Kris, who has been close to him since their childhood.
Rudy's Undertale counterpart fell down (i.e. died) very suddenly. This means that if Rudy died of a similar illness in the Undertale timeline, it probably wasn't chronic. However, Deltarune establishes that Rudy has been in hospital for long enough that it's semi-standard for Noelle to visit him there (rather than at home). Nevertheless, it's possible that Rudy originally contracted an acute illness, only to never really get better, or for the acute illness to trigger the onset of a chronic condition.
Finally â a scrapped version of Noelle's room in chapter 2 shows pills on Noelle's table. These could, theoretically, be her pills. However, given some of Noelle's more worrisome dialogue in chapter 5, it's possible that if these pills have a Light World equivalent, they could be Rudy's pills (stockpiled for extremely concerning reasons). This is supported by the presence of two different pill bottles and several pills spilled on each table, as if to be counted. If these are Rudy's pills, this would imply he's been ill long enough to have several months' worth of prescriptions.
What can we gather from this? Probably that as long as we disregard the RudyKnight theory, we can say that Rudy's illness probably began as something acute, but that it's now progressing, and that while he doesn't have a terrible prognosis confirmed, he's probably not going well.
