[@Tsukoreyu]

No. Great Tree Arc is..well an arc. regardless it is a Lost Magic. None of the GMs are in favor of characters having two powerful Lost Magics on one character. We would like you to choose one. It is also an understanding that it depends on the character and the magic that you choose. Though for such high level magic like Great Tree Arc and Crash, we'd feel better if they weren't used together on one character. Similar story if someone tried to use a Slayer magic + another high level magic like Territory Magic.