In this paper we analyze the structural and linguistic dynamics of online toxicity in Reddit discussion trees, focusing on how trigger comments escalate conflicts in Brazilian Portuguese. Using a fine-tuned BERTAbaporu model, we show that toxic discussions are deeper, more engaging, and initially semantically cohesive, but degrade over time, while non-toxic interactions emphasize social bonding. Our findings contribute to a better understanding of toxicity escalation and support early detection of discursive conflicts.