Ursaring is classified as a 2-Diamonds card in the Wisdom of Sea and Sky set
Binding is much too slow comparatively, so one should be focusing on what they can abuse by milling over six cards for only two mana
And double crisis Sealed blisters and sets of double crisis in english and japanese: I do have probably a full set of double crisis (I opened a lot when they came out) and maybe in the far FAR future I will attempt to complete a graded set of them, but for now I want to focus on the humans in the teams and any cards I can find with their faces on
However, there are potentially better cards with similar abilities, such as Bronzong from the same set, which offers a more consistent energy acceleration option
The last card I want to touch on in this section is also the only Rare (non-Mythic) on the list: This is another creature that can completely warp a game in Standard - the Bird Wizard hits fast and hard, leading to some crazy, out-of-nowhere attacks for double digit damage
If you mean 'challenging' other characters, or glimmers, in play Steel and Ruby are good at challenging and can get benefits for banishing opposing characters during challenges
