Enchantments and artifacts that boost your creatures stats, as well as any kind of typal advantage, will definitely work well within a mouse deck
Of all the precons, Counter Blitz is clearly the most focused on a singular goal, and nearly all the card choices are aimed at synergy with its Counter theme
This attack requires two Energyone Darkness Energy and one Colorless Energymaking it slightly less efficient than other cards on this list
But they arent just hanging around to add some flavor to the expansion
That does not mean, as we have explained before, that the metagame is static, but if you invested in Regidrago when it first came out (like 4 or 5 years ago), you would have had in your position a tier 1 or 1.5 deck ever since
The relative scarcity of these different treatments is not considered part of the card's rarity