Typcial "take-no-chances" logic from Prime when it comes to ALL recovered I-Tech: better off stored in the Vault - or in a card deck box in the Monster Reborn magic card's case - than letting it all fall into enemy hands. Of course, Smokescreen would one day come in and bust one out - saw him put the Phase Shifter to good use, making Screamer kiss his Apex Armor goodbye.
Goodness, I just caught up. This is a lot of fun and really hilarious. It's such a shame that Optimus' logic sucks.
I'm not sure if an official version of Slifer even exists, although I think there is an official Obelisk now, which is kind of neat.