They were all systems. Bastian liked to see them as a programming language. Each method was one language, so to link the four main methods; one would need a completely new language to link them up with.
Bastian's idea was to use earth mathematics. He wanted to find a way to link runes, hand seals and chants. Thus, he decided to use mathematics, something he was all too familiar with. He went through everything he knew, from calculus to trigonometry. Then when he finally found a way to link up the languages with mathematics he came up with a brilliant idea. A compression algorithm!
"I used a compression algorithm! Observe!" said Bastian. He immediately removed his robes, and stripped himself of his underwear, allowing Kenshin to see everything. At the soul site, they were naked, so Kenshi
