By the time you finally reach Caltheris in the Astra Malorum quest, you have already learned the map inside out, probably wiped a dozen times, and maybe even checked a CoD BO7 Bot Lobby guide or two. The fight itself is not the place to improvise. If your squad is not clear on what each phase needs, the arena turns into a mess of lasers, zombies, and people yelling over comms. So you want to walk in already knowing when you can actually hurt the boss and when you are just wasting ammo and getting yourself killed.
Phase One – Filling The Soul Box Under Fire
The opener catches a lot of players out. Caltheris is floating high above the arena and looks like a big target, but you cannot damage him at this point, so do not bother dumping Wonder Weapon shots into the sky. Your job is crowd control. There is a soul box over by the edge of the arena and it only charges if zombies die right next to it. You quickly realise the real threat is not the undead but the constant laser beams Caltheris fires across the floor. Keep moving in loose circles around the box, drag the horde with you, then pick them off when they bunch up by the device. When your screen flashes blue, that is your signal the box is ready. Run up, activate it, and you will see a huge chunk ripped off the boss’s health bar. You have to repeat that whole loop three times, so staying calm and not overextending is what keeps the team alive.
Phase Two – Grounded Beast With Weak Spots
Once you knock him out of the air, Caltheris slams into the arena and turns into a proper tanky monster. This is where the fight feels more like a classic boss. You will see glowing weak points appear across his body, usually on the arms, shoulders, and chest. Aim for those first. You do not need fancy tricks here, just consistent damage and clean positioning. After you pop enough of the smaller weak spots, a much larger one appears, and that is when you want to dump your strongest bursts – LGM-1 charged shots, Ring of Fire, whatever your squad has been saving. The one move that really punishes greedy players is his boulder throw. He locks onto a single person, so as soon as you see him pick up a rock and stare you down, sprint hard sideways and do not try to finish your mag.
Phase Three – Caltheris Ascendant Gets Meaner
Phase three, Caltheris Ascendant, looks similar at first glance. Bigger model, louder effects, same glowing targets. The big change is the ground slam. He winds up, jumps, and if you are too close or too slow getting out of the impact zone, you are probably getting downed in one hit, especially on higher rounds. A lot of players get caught staring at weak spots and forget to watch his hands or feet for tells. You want to keep a loose spread as a team, avoid stacking in one corner, and call out when you see him start the slam animation. The pattern is still the same – break the small weak spots, burn the big one when it appears – but the room for error shrinks fast, so revives and self-res are usually burned here.
Needle Phase – Purple Pools And A Clutch Power-Up
The Needle phase is where runs often fall apart even though the mechanics do not change that much. Caltheris keeps the boulder attack from earlier, but now every rock he throws leaves behind a purple pool on the floor. Stand in one for more than a second and your health melts. Space management suddenly matters more than raw DPS. Try to drag those pools to the edges of the arena instead of the centre, so you do not block your own escape routes later on. During all this, the brain jar drops a special power-up that is basically a mix of Insta-Kill, Max Ammo, and a full Field Upgrade charge. The temptation is to grab it as soon as it lands, but it is way stronger if you hold it until you are running low on ammo or about to get overrun. Call it out to the team, agree who is going to pick it up, then use that window to focus fire on the last weak spots and finish Caltheris off while the buffs are rolling, turning a chaotic final stand into a clean clear with help from u4gm CoD BO7 Bot Lobbies level prep.
