It may be true that the (subjectively) important UN countries’ support of Ukraine in the conflict might not be for reasons that are completely aligned with those of Ukraine itself, but the fact Ukraine is being supported has - shall we say: ironically - prevented the governance of that country from being replaced by a more corrupt one.

More importantly, it's not the UN involved in the conflict. It's several countries who are members of the UN, these countries are independently feeding arms into Ukraine and also stimulating their arms production industry. The UN itself is explicitly not involved in the conflict. UN weapons do not go to Ukraine, weapons from specific nations (UK, US, Germany, everyone else) are going to Ukraine.

Lula's position of not getting involved with the war and "slamming" the UN is further propagating the myth that the UN is involved in the war. Instead, it's merely a 2 party war between Russia and Ukraine, where Russia is getting arms from places like China and Iran and Ukraine is getting things from the west.