That's fine! I wasn't expecting him to be able to be out a long period of time to start with anyway, so that's totally fine.

So just to make sure I have it clear: With this echo, he can be summoned for short bursts (with long cool downs between), intangible so he doesn't knock down the walls just by existing. With a later echo, can gain the ability to turn invisible. Other abilities [such as being able to extend that intangibility and invisibility to Bakura as they were in canon] will be accessible via other echoes after a longer wait time (like a month or so.)