Many people use the phrasing "may the Neshama have an Aliyah" at a shiva, shloshim, or yahrtzeit celebration. Which aliyah is better to give to the deceased? Shlishi, Shishi, or Maftir?

Also, when calling up the deceased for the Aliyah, does one change the formula to include an indication that they have passed?

This question is Purim Torah and is not intended to be taken completely seriously. See the Purim Torah policy.

You get maftir, thereby making them the niftar.

There is an ancient custom of burying deceased Jews in Israel, dating all the way back to Yaakov Avinu. When people say this phrase, they are expressing their wish that the person will make aliya, so to speak, and be buried in Israel. If the person has already been buried, the bracha is still applicable as even the original occurrence of this practice involved exhuming the body and transporting it to Israel.

You get Levi aliyah. And this is regardless of whether you're a Levi or not.

The reason is that in a sense, during yahrtzeit, the spirit or "memory" of the dead person comes back down to Earth to be with you. After the yahrtzeit you need to do לויית המת and "accompany" the spirit back to heaven.

As a matter of fact, even a Cohen should get the Levi Aliyah and not the Cohen aliyah. If he were to get the Cohen aliyah, you would be indicating that he can't do לויית המת. That's not true in the case of a parent or close relative. If, for some reason, he were commemorating the yahrtzeit of a non-close relative, then, yes, he should keep his regular Cohen aliyah.

The Mishnah (Gittin 59a) says:

כהן קורא ראשון ואחריו לוי ואחריו ישראל מפני דרכי שלום

A Kohen reads first, then a Levi, then a Yisrael, because of the ways of peace.

The Gemara (ibid. 59b) explains:

לא שנו אלא בסעודה אבל בבהכ"נ לא דאתו לאינצויי

They only taught [that one waits to accord respect] by a meal, but in a shul, we do not, for people will come to quarrel.

When coming to honor the deceased, everyone is obligated to pay their respects, and so there's no concern for quarrel; therefore, the deceased gets the first Aliyah. This is indicated by the Gemara's following question and answer:

והא רב הונא קרי בכהני בשבתות ויו"ט שאני רב הונא דאפילו רבי אמי ורבי אסי כהני חשיבי דא"י מיכף הוו כייפי ליה

Rav Huna read the Kohen aliyah on Shabbos and Yom Tov! Rav Huna is different, for even R' Ami and R' Asi, the most distinguished Kohanim in Eretz Yisrael, would bow to him.

Since everyone would pay respect to Rav Huna, he could take the Kohen aliyah, even without being a Kohen himself. So, too, since everyone pays respect to the deceased, he gets the Kohen aliyah.