[Solved] How to revive Hardcore Character ?

You can use Hero Editor or ATMA II to edit .d2s character file (from charsave dir).
But it also needed to edit charinfo file.

There is only a single byte at position 180(0x84) that value should be set to 101(0x65) to set a character state to hardcore+ladder+undead. Or set value to 37(0x25) to hardcore+nonladder+undead.

// set ladder and dead flags
//  $softcore (softcore = true | hardcore = false)
//  $ladder (ladder = true | nonladder = false)
//  $dead (dead = true | live = false)
//  $charinfo (charinfo = true | charsave = false)
public function setLadderDeadFlag($softcore = true, $ladder = true, $dead = false, $charinfo = false) 
{
    $type[0][0][0] = 37; // hardcore - nonladder - live
    $type[0][0][1] = 44; // hardcore - nonladder - dead
    $type[0][1][0] = 101; // hardcore - ladder - live
    $type[0][1][1] = 108; // hardcore - ladder - dead
    
    $type[1][0][0] = 33; // softcore - nonladder - live
    $type[1][0][1] = 40; // softcore - nonladder - dead
    $type[1][1][0] = 97; // softcore - ladder - live
    $type[1][1][1] = 104; // softcore - ladder - dead
    
    // position
    $pos = (!$charinfo) ? $pos = 36 : $pos = 180;

    $value = chr( $type[$softcore][$ladder][$dead] );

    $this->setValue($value, $pos, 1);
}

pvpgn.harpywar.com/d2s/d2save/charsave.class.txt