What is the message that the characters of Mahabharata war (Pandavas) give through blowing their conch shell?

Tatahsvetairhayairyukte,mahatisyandanesthitau;
madhavahpandavascaiva,divyau sankhau pradadhmatuh

                                         ….. B.G.CHAP 1 VERSE 14

After the Kaurav, Krishna and Arjun, riding in their magnificent, sacred chariot drawn by flawlessly white horses (“white” symbolizes purity), also blow their “celestial” conches. “Celestial” means beyond the material world. Yogeshwar Krishna’s transcendental message is a promise to render unto souls the most auspicious, unworldly existence that is beyond the worlds of both mortals and gods, and verily the whole universe (Brahmlok), which is all afflicted with the fear of birth and death. If the words in this verse are carefully looked at they indicate something…It says the chariot is celestial (not made of gold or silver) conch is celestial, everything is pure and celestial so the poet wants to state that their message is also celestial.

Beyond these worlds there is only the one unique and indescribable God. Krishna’s message is of establishing a direct contact with this Supreme Being. But how will he affect this state?

Pancajanyamhrsikeso,devadattamdhananjayah;
paundramdadhmaumaha-sankham,bhima-karma vrkodarah

                                              ….. B.G.CHAP 1 VERSE 15

So Hrishikesh (lord of the senses), who knows all the mysteries of the human heart, blows the conch PANCHJANYA. This is a declaration of his intent to restrain the five organs of perception which correspond to word, touch, form, taste, and smell, and to transmute their inclinations into devotion.

ARJUNA or Dhananjay (the victor of wealth) is the affectionate devotion that attains to the state of divine exaltation. This devotion is a feeling of tenderness for the desired object, which includes within itself all the experiences of devotees, even pangs of separation and occasional disenchantment and tears. There should be nothing for a devotee except the longed-for God. If the devotion to him is perfect, it embraces the virtues (DEVDATTA) that provide access to the Supreme Spirit.

BHEEM of awesome deeds blows his great conch PAUNDR, which denotes sentiment. The heart is the spring as well as the habitat of feeling. This is why Bheem is called Vrikodar, the large-hearted. Sentiment is fathomless and mighty, and this sentiment is Bheem’s great conch that is now blown. The affection that he represents is embodied in sentiment. That is why Bheem blows the conch named Paundr.

Anantavijayamraja,kunti-putroyudhisthirah
nakulahsahadevasca,sughosa-manipuspakau

                                     ….. B.G.CHAP 1 VERSE 16

King Yudhisthir blows the conch Anantvijay (endless conquest). Kunti is the very image of dutifulness; and Yudhisthir, the embodiment of dharm (natural piety). If one’s adherence to dharm is steady, Anantvijay will bring about the absorption of the Self in the boundless God.

Nakul, who is a symbol of restraint, blows the conch named Sughosh. As restraint grows firmer, evil is subdued and the dominance of righteousness is proclaimed. Sahdev, the adherer to truth, blows on the conch which bears the name of Manipushpak. Sages have described each breath as a precious ruby. “What a pity that we squander the jewels of our breath on idle gossip!” One kind of satsang is the moral discourse we hear from noble men, but the real spiritual discourse is internal. According to Krishn, the Self alone is true and eternal. True satsang comes about when the mind reins itself in from all externals and dwells with the Self. This adherence to truth is cultivated by incessant reflection, meditation, and samadhi. The more joy one feels in dwelling with the one reality, the more restraint one gains over each breath, the mind, and the instruments by which objects of sense affect the Self. The day they are totally restrained is the day when we are absorbed in the ultimate essence. Providing, like a good instrument, harmonious accompaniment to the song of the Self is true satsang. The physical ruby is hard, but the jewel of breath is even more tender than a flower. Flowers fall and wither soon after they bloom, and we can never say that we shall live until the next breath. But if there is true adherence to the Self, it leads us to realize the highest goal through providing control over each breath. There is nothing to proclaim beyond this, although each device is helpful in traversing a certain stretch of the path of spiritual perfection….OM TATSAT