Other "Benefit" and "Invisibility" characters weren't too difficult to form Word Symbols from, it's just that there might be slightly fewer types of Word Symbols available.
For Ze, being able to use Word Symbols was already a significant enhancement. Yu Liang still chose to focus more of his thinking on the Word Symbols that he and "It" could use.
Having received Yu Liang's guidance, Ze left the camp tent contentedly; his main reason for coming over so sneakily was to copy homework.
Just seeing Little Fairy Maiden driving a Tank, one could know that Yu Liang must have concocted some good stuff. Ze was aware that he needed to consume Impure Points if he wanted to synthesize Word Symbols, so he couldn't be bothered to slowly experiment with the usage methods of Word Symbols.
After Ze left, Yu Liang finally turned his attention to "It": "How is it, are the Word Symbols useful?"