Every upkeep you can choose to put a charge counter on it, then tap it to put a creature into play with a converted mana cost equal to the number of charge counters
There are lots of moving parts in this deck but to put it simply, the heavy ramp focus allows you to quickly build your board and Omos capacity to tack an everything counter on lands and creatures has plenty of opportunity for payoff
For fast mana, you can swap Mox Diamond and Chrome Mox for cards like Jeweled Amulet, Coldsteel Heart, or even Izzet Signet if you're prioritizing colored sources
If the attacking creature has deathtouch, it would only need to assign one damage to each blocker
Saffgor: I think this could see play in decks running cards like Tifa, where the doubling gets you over the hump to kill, and removes a problematic blocker
If it happens to deal combat damage to you (usually due to a redirection effect, which would be unusual), the ability wont trigger.