Honestly, doing a direct conversion of the game may prove too difficult (given just how much averaging and multiplication is done behind the scenes in game). An easier approach might be to convert Destiny over to another game system, keeping what mechanics you can from the game, and building the rest from scratch. This way you can try to maintain the "feel" of Destiny, even if mechanics differ somewhat. I myself am currently working on a conversion similar to D20 Modern using a system my friends and I developed over the last year or so. Even that is proving tricky to find a solid balance between staying true to the heart of the game and the crunch of how it is played. 'Hope this helps somewhat.