While absorbing X-Parasites is automatic, you can optimize it. If you're low on Energy, prioritize yellow X-Parasites. If low on Missiles, prioritize green. Red X-Parasites are rare and provide a full refill of both. In rooms with many enemies, try to defeat them in quick succession to create a cluster of X-Parasites, then absorb them all at once for maximum benefit. Avoid letting X-Parasites re-animate enemies if you're low on resources.
