For early digivolving steps we recommend [EX8-050 Gogmamon] and [EX8-053 BanchoGolemon], which can block the opponent's attack and if deleted the [On Deletion] effect can bring a new Digimon into play to keep up the defense and increase the trash at the same time
Doras protection effect doesnt necessarily have to be used on itself either - sometimes the correct play is to have it protect another monster you have, like Liebe or Zeus to avoid being hit by an opponents removal effect, or even targeting an opponent's card to prevent your opponent from interacting with it and using it to combo
Upgrades are cool, but they really only increase the quality of interaction available, not the quantity
DARK & EARTH: Return the 1 monster with the lowest DEF on the field to the hand (your choice, if tied)
When you factor in additional enchantment drops beyond that, things get downright silly
It draws you a card for each legendary spell you cast, then it transforms into Hydaelyn, the Mothercrystal, granting indestructible and more draw for legendary creatures