Use the gem or save it?

I have Hulk, titanium, and futon awakened. Should I use this on one of these or wait? I have two of the awakening gems and human torch fully maxed as a five star. Thoughts?

I have Hulk, titanium, and futon awakened. Should I use this on one of these or wait? I have two of the awakening gems and human torch fully maxed as a five star. Thoughts?