LJUDSBÁS ~ βασιλεύς

Silver coin (4 drachme, ca. 305-283 BCE, Alexandria) 

with portrait of Ptolemy I Soter: "PTOLEMAIOU BASILEOS"

wikipedia:

Basileus (Greek: βασιλεύς) is a Greek term and title that has signified various types of monarchs in history. [...]
The etymology of basileus is unclear.

The following clue is worth considering, in my opinion:

Source: Das magusanische Europa, oder: Phönizier in den Innen-Landen des europäischen Westens bis zur Weser und Werra: Skythisches Einvolk und Einsprache in Hoch- und Vorder-Asien, Nord-Africa, spaeter Ost- und West-Europa, Volume 4 (1834), Wilhelm Gottlieb Levin von Donop (p.197: list of "Semitische und Gaalische Herleitungen")

Not all suggested etymologies in this list are convincing, but this one is, to me: 

Bas-Luis = Vorstand des Volks (German) = president/ leader of the people
LJU(D) or LJV(D) in OLB, see earlier post about HÉRLJU - Heruli.
hljóð - icelandic
ljuda - swedish
lyd - norse, danish
lui, lieden - dutch
leute - german

(note the name LJUDPOLD - Luitpold - Leopold)

The Online Etymology Dictionary has:

boss - "overseer," (...) from Dutch baas "a master," Middle Dutch baes, of obscure origin.

And on the dutch Etymologiebank it says (translated):

baas - leader, head of something (...) of unknown origin (...)
There are no related words in other Indo-European languages.
It is probably a word from a non-Indo-European substrate.
Derived from Dutch are:
boss, base, bass - english
bas, baß, baas - german
bas - danish, swedish, norse

Are established etymologists paid to play dumb?

Basileus = luisbaas (dutch) = LJU(D)S.BÁS (fryas)

Here are the OLB fragments with BÁS (master, boss, etc.), four of which referring to the Mágí (fragments 4, 5, 6, 7):

1 [002/26]
THA BÁSA ÀND HJARA STORSTA SVNUM
KRUPTON BY THA LODDARIGA FINNA MANGÉRTUM.

2 [036/19]
THÉRVMBE KJASTH VS FOLK SIN FORSTA. GRÉVA. RÉDJÉVAR
ÀND ALLE BÁSA ÀND MÁSTERA UT.A WISESTA THÉRA GODA MÀNNISKA

3 [038/04]
THAT ALLERMANNALIK THÉR HJA HÉRA WILDE RIK ÀND LUKICH SKOLDE WERTHA.
ÀND ÉNIS BÁS SKOLDE WERTHA OVIR ALLE KÉNINGKRIK JRTHA.S
 

4 [079/14]
THRVCH WODINS DOR ÀND DERTENHÉD
WAS THENE MÁGÍ BÁS WRDEN OVIR SKÉNLANDIS ASTAR DÉL.

5 [081/16]
THENE MAGÍ WRDE BÁS

6 [084/27]
IK HÀV THI FRÉJETH JEFTH IK BÁS SKILDE WERTHA
OVIR ALLE LÁNDA ÀND FOLKRA FRYAS

7 [115/04]
THRJU JÉR LÉTTER WÉR THENE MÁGÍ BÁS. SVNDER STRID

8 [122/02]
ALSA NÉARCHUS THÉR SELVA NÉN BÁS OVIR BILÍWA NE KV

9 [141/13]
THÉR NE SKILUN NÉNE ORA MÁSTERA NACH FORSTA NER BÁSA NAVT NÉSA
AS THÉRA THÉR BI MÉNA WILLE KÉREN SEND.

10 [190/30]
JAHWEDER MÀN IS THENE FÉDER FON SIN HÛSHALDEN
HÉRVMBE SKIL.ER ÁK BÁS ÀND RJUCHTER OVIR WÉSA.