It's a bit interesting because in Ice Age we've seen via Soldevi Simulacrum that they were able to create very humanoid-looking artifact creatures, so these things are probably walking around like T-1000s just for intimidation factor
Generally, managing this involves disrupting what the combo deck is trying to do, as their kill will be faster than yours if left unchecked
But if you can potentially deal more than 20 damage in just two turns, with a "cashback" if the opponent does try to delete your pumped creature, then the dice usually becomes well worth rolling
You see, Dialga is a more complex, combo-oriented Standard deck than many other Standard lists at the moment
It also has the useful attack Chaos Wheel, which for the cost of 1DCE, 1-grass, and 1-psychic, deals a damage of 100, while also locking the opponent from using any Stadium, Tool, or Special Energy card during their next turn.
Since its not Legendary, many players will be after the full set of Demilich since youll want to cast the creature as regular as possible in a game of MTG