Although the Elemental Dragon's projected avatar had intervened, and made it impossible for Xiao Hua to completely become Lin Li's summoned creature, the soul contact between the two was incomparably strong because of that wisp of Soul Brand.
It was naturally very difficult for Xiao Hua to assimilate the Soul Brand on its own, and it could even be considered impossible. However, Lin Li could protect Xiao Hua's soul directly using soul contact. That would drastically increase the success rate. Lin Li might have just stepped into the Sanctuary-realm, but in terms of mental strength alone, perhaps even the three great arbitrators would not be able to compare with him.