Wuhaoyu said:
Nothing the Imperium can do could stop such a horde. It would leave behind it a dead galaxy, every trace of life extinguished. Even the Chaos realm would be gone. The tyranid hive mind has no soul, no spiritual counterpart. When it moves through the warp, it is like a wall erasing everything in its path. The tyranid is the universe's ultimate life-form, depending on infinity itself to sustain its eternal existence. The tyranid themselves are infinite in number for all anyone knew. In the face of such a vision the whole of mankind, even the Emperor Himself, seemed helpless and insignificant.
- Eye of Terror
https://vsbattles.fandom.com/wiki/The_Emperor_of_Mankind
Even The Emperor of Mankind is 1B´╝îmaybe 1A .If they are real 1B and 1A´╝îlike Q´╝îthey can stop tyranid. The Emperor of Mankind able to hold off
the four Chaos Gods from breaking into realspace´╝îbut are real 1B will not because this can't stop tyranid
Trying to downgrade chaos god and the emperor through Tyranid is not wise. Tyranid has a hive mind, which itself was ranked 1-B due to the only description saying that its tendrils coil around dimensions. We do not even know how large is it's presence in the warp. If your quote is valid, then it only makes hive mind 1-A together with the chaos gods instead of denying their present ranks.
Hell, lots of people are unhappy about how gods in Warhammer are ranked simply because the story takes place in a galaxy. They feel unbalanced when they see that such gods are ranked above a lot of other beings from Xeelee, Marvel, SCP, DC and so on. Those people accept only the lowest-end of the feats and descriptions, so warhammer gods can be limited to star system level as they wish. You seem to be one of them, but that is not how things work. If you want to see Xeelee win, then go make another thread that does not compare them with Warhammer gods.
Edit: By the way, if you are not good at English, I recommend you to use google translate so we can understand your posts more easily.