This is simply a snowballing process, using vast low-tier troops to flatten one powerful monster after another, then recruiting hundreds or even thousands more powerful undead monsters.
If it weren't for quietly building up strength, he would have broken out of the Silent Sewer long ago!
And the arrival of Lin Rui further provided him a great opportunity to grow stronger, as Lin Rui had not one, but two [Colonization Marks]!
Absolutely unique among the Explorers invading the Colonization Star.
Therefore, Matthew directly launched a massive Undead Catastrophe wave, intending to flatten Lin Rui completely.
This terrifying catastrophe includes millions of Tier Three Ghouls, with potentially billions of Skeleton Spearmen, not to mention millions more Burrow Demons, Corpse Witches, Vengeful Spirits, Zombies, Bat-winged Demons, and even Death Knights and Terror Knights.
Even Tier Six Heroic Spirit-level Bone Dragons number in the thousands!
