Griezzo is bad in the current meta...
To make an accurate tier list you have to understand what makes good cards. There's a strong preference in the meta for cards that can win fights.
There are basically 5 types of cards in UR:
1) Outdated -- card has low base stats or such poor stat/ability/bonus synergy that it is not playable in
ELO
2) Well-rounded -- card is okay in every regard, no particular strength or weakness, no need to discuss
3) Wall -- card has high round-winning power, but either low or situational gapping ability
4) Glass Cannon -- card has low or situational round-winning power, but high gapping ability
5) Powerhouse -- card has great base stats, good round-winning power and gapping ability
Griezzo is the 4th kind of card; he will always lose to the Beeboys and the Askais, he will always lose to the well-rounded cards like
Shifou, he will always lose to cards with high round-winning ability like Chiara. At some point in the not-too-distant past the 4th kind of card were more or less playable, but now they are rapidly disappearing from the meta. As UR's power creep continues, the 2nd, 3rd, and 5th kind of cards just get better at winning rounds, and even once great cards of the 4th type (
Nyema,
Oflgn, etc) are starting to look much less ELO-playable, because they are easy to beat.