Korah Will Return
Perek R' Yoshiyahu (see p. 203 of Otzar Hamidrashim - my translation):
...Eliyahu Zachur Latov will perform 7 miracles at that time [when Mashiah arrives - to prove that he was sent by Hashem]:
The first miracle - he will bring Moshe and his generation from the desert. This is alluded to from what it is written (Tehillim 50:5)אספו לי חסידי Gather My saints together unto Me.
The second miracle - he will bring up Korah and his entire congregation, as it is written (Tehillim 71:20) תשוב תחינו ומתהומות הארץ תשוב תעלני wilt quicken me again, and bring me up again from the depths of the earth.
The third miracle - he will make stand Nehemia Ben Hushiel [Mashiah Ben Yosef], who was killed in the gate of Yerushalayim.
The fourth miracle - he will reveal to them the hiding place of the Holy Ark, the jug of Manna, the Menora [המחורה?] with its 7 candles upon it, and a jug of the annointing oil.
The fifth miracle - Hakosh Baruch Hu will place a rod of strength in his [probably Mashiah's] hand, as it says (Tehillim 110:2) מטה עזך ישלח ה' מציון רדה בקרב איביך The rod of Thy strength the LORD will send out of Zion: 'Rule thou in the midst of thine enemies.'
The sixth miracle - he will pulverize all the mountains of Israel like flour, as it is written (Yeshaya 42:15) אחריב הרים וגבעות וגו I will make waste mountains and hills [and also written in] (Habakkuk 3:6)עמד וימדד ארץ [ראה ויתר גוים ויתפצצו הררי עד] וגו He standeth, and shaketh the earth, [He beholdeth, and maketh the nations to tremble; and the everlasting mountains are dashed in pieces]
The seventh miracle - he reveals to them the Sod [secret], as it is written (Yirmiyahu 31:32) כי זאת הברית אשר אכרת את בית ישראל [אחרי הימים ההם] וגו But this is the covenant that I will make with the house of Israel [after those days] ...
Fortunate are those who see those days.