// Create the var
new PlayerAntiSpawn[MAX_PLAYERS] = 0;
new Timer;

// Process p1->Player Spawns
public OnPlayerSpawn(playerid)
{
    // p2->SetTimer
    Timer = SetTimerEx("OnPlayerAntiSpawn", TIME_TO_WAIT, false, "d", playerid); // Change TIME_TO_WAIT to the time in ms you want.
    PlayerAntiSpawn[playerid] = 1;
    return 1;
}

// Process p3->OnPlayerTakeDamage
public OnPlayerTakeDamage(playerid, issuerid, Float:amount, weaponid)
{
    if(PlayerAntiSpawn[playerid] == 1) // p4->Check var
    {
        GivePlayerHealth(playerid, amount);
        return 1;
    }
    else // p5->Otherwise don't
    {
        // Other code.
    }
    return 1;
}

// p6->KillTimer/Var

forward OnPlayerAntiSpawn(playerid);
public OnPlayerAntiSpawn(playerid)
{
    PlayerAntiSpawn[playerid] = 0;
    return 1;
}

public OnPlayerDisconnect(playerid, reason)
{
    KillTimer(Timer);
    PlayerAntiSpawn[playerid] = 0;
    return 1;
}