How do you get Inferlupa?

Plan for three separate sessions rather than one long one. The mission stages sit behind the daily server reset, so the pattern is: log in, clear whatever stage has unlocked, come back the next day. Nothing you do on day one shortens day two. If you are chasing this creature for a specific reason, start the quest as early as you can, because the calendar does the gating, not your level or your gear.

You will also see this form written as Infernal Lupa and as Enfurloopa. They are the same evolution, and searching under any of those names is looking for the same three-day quest.

Emberpup's two branches

Inferlupa sits at the end of one branch off Emberpup, and Emberpup does not evolve in a straight line. Branching Aniimo offer two path options, and which one you get is decided by the choices you make during the quest and the items you have collected along the way. The other branch runs into Flameruff and continues to Scorchhowl, also written as Scorch Howl.

That matters because the decision points sit inside the same three-day questline. A wrong choice or a missing item on day two is not something you can fix by grinding harder on day three.

Collecting before you start

Since collected items feed into which branch you take, it pays to have evolution materials in hand before the quest begins. Evolution stones come from defeating Gamma and Nova stage Aniimo, so fighting them out rather than capturing them is how you build a stock.

One drop is worth knowing about on this line specifically. Defeating a Gamma-stage Flameruff, instead of catching it, has a low chance to drop an Unbroken Flameruff Spirit in place of an evolution stone.

Not settled: Emberpup's branch structure is not fully settled yet. The line is described both as running into Inferlupa and as running into Flameruff and then on to Scorchhowl, so exactly which decisions send you down which branch is still being pinned down.