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The paper presents new results of the ongoing study of the unusualLynx-Cancer void galaxy DDO 68 with record-low-metallicity regions (12+log(O/H)~7.14) of the current star formation (SF). They include: a) a new spectrum andphotometry with the 6-m SAO RAS telescope (BTA) for the Luminous Blue Variable(LBV = DDO68-V1). Photometric data sets are complemented with those based onthe Sloan Digital Sky Survey (SDSS) and the Hubble Space Telescope (HST)archive images; b) the analysis of the DDO~68 supergiant shell (SGS) and theprominent smaller H-alpha arcs/shells visible at the HST image coupled withkinematics maps in H-alpha obtained with the Fabry-Perot interferometer (FPI)at the BTA; c) the list of identified at the HST images of about 50 mostluminous stars (-9.1 < M_V < -6.0 mag) related to star-forming regions with theknown extremely low O/H. This is intended to pave the path for the actualscience with the next generation of giant telescopes. We confirm the earlierhints on significant variations of the LBV optical light deriving its amplitudeof dV > 3.7~mag for the first time. New data suggest that in 2008--2010 the LBVreached M_V = --10.5 and probably underwent a giant eruption. We argue that thestructure of star-forming complexes along the SGS (`Northern Ring') perimeterprovides evidence for the sequential induced SF episodes caused by the shellgas instabilities and gravitational collapse. The variability of some DDO~68luminous extremely metal-poor stars can be monitored with medium-sizetelescopes at sites with superb seeing.

Extremely metal-poor galaxy DDO 68: the LBV, H-alpha shells and the most luminous stars