You dont end up losing one of the creatures for good, and you also become the monarch, giving you some extra card draw
Take a look at Capricious Sliver, Hatchery Sliver, Lazotep Sliver, Regal Sliver, and Taunting Sliver
Stratus Dancer loses a lot of power if its the only morph anyone plays, but you can wreck people with a hidden on-board counter that cant be countered back without serious work
From here, each new batch of tokens you create will get you more draws, making already strong cards like Voice of Victory and Adeline, Resplendent Cathar even better
Cards like Blade Historian, True Conviction, and Legion Loyalty can all help push your combat prowess to its limits by giving your creatures powerful keywords
Auras, equipment, and adding counters are the easiest to understand, but there have been other, stranger experiments