Probably thaumiel, he would be impossible to be contained, but may be useful in kicking the butts of other SCPs

1, To the previous reply... What? That is not how the Thaumiel category works, as it serves as a way to protect humanity at large, never to directly fight SCPs. The SCP Foundation doesn't do that type of thing.

2. I'd imagine Keter, myself. If you put him in a box, he'll definitely try to get out, in use of that way to symbolize rankings.

ngl, keter's gonna be the reasonable one here

they obviously have weapons to combat against tricky's immortality, and reality warping feats as shown in the MC series

though eh, they'd need some serious shit to actually contain the guy in a steel box or something.

Keter does fit Tricky more, but he’ll be one of those Keters who are nigh impossible to contain. Although he might be easy to contain if the foundation bribes him with hotdogs, cookies and tea.

Id say apollyon hes a god so it would make sense

Apollyon, he literally can control the reality lol

I think that it's a scp XK bc of its powers