Why is Deirdre tier 6?

I love Deirdre so much... i understand this outrage.

I think she's T6 because she's anti-meta, and that means she lives & dies based on how the meta shifts & rotates. There aren't that many dragons running around right now, nor is Reinhardt as deadly as he was, so everything Deirdre counters is no longer "meta" at least for now.
That said, I don't think she deserves to be in T6 since she does her anti-meta job better than, say, Julia.
I understand why she's plummeted, I just don't think it should've been that far of a fall for her.
But even I noticed that my beautiful forest wife is spending more time on the bench than she did a few months back. Just some slight meta shifts that affect her so much purely because her role is as an anti-meta unit.

The current meta doesn't value ranged units due to having poor BST. Deirdre also doesn't have any specialties; Her Atk and Spd are too low to run Bladetomes, and her Def is too low to run CC and Gronnowl. All she has left is her Res, which won't be very useful due to magic units being uncommon in high tier arena. She doesn't have access to the high BST and valuable skills of Armor units; which is why Halloween Henry, Nino, and probably Lewyn are generally the best green mages of Arena; Nino is a specialised Bladetome nuke H!Henry can run a nasty tank build with Vengeful Fighter, Owltome, and Close Counter, and Lewyn is pretty much Greenhardt.

Yeah i disagree with many unit's placements on the tier list

I have a feeling you're a big fan of Deirdre.

The meta right now is very Spd focused(unless we're talking about Armors then Spd is irrelevant to them).

When you look at teir 1 and 2 most of them are either fast and hits hard or armored, and Deirdre does hit hard but is'nt fast and that's why she is tier 6 and mages Nino it's because they are launch units that thye are "outshined" by the newer units that can do the same thing as she does. I'm not saying I agree to it, I'm just saying why she is placed like that(from my observations)

And don't bother with the Teir list \.If you don't agree to the teir list then it's fine cause the teir list is made by the "OPINIONS" of other people and not everyone will agree to opinions.

i guess its all about beeing slow and having low BST? Although Rienhardt wasn't affected by those factors, but thats thanks to brave tome.
Also you should not compare Nino and Deirdre because they tend to play differently, Nino is offencive powerhouse meanwhile Deirdre is baiter, who shines in enemy phase.

While her stat line isn't that bad you have to note that her physical bulk is way too low, she dies from anything that hits her def, and she may even die from dragons which she should be killing:
- red dragons will straight up oneshot her on the counterattack
- green dragons will kill her if she doesn't double, and if she attacks Grima or Myrrh she has no chance of killing them
- even blue dragons may kill her if she is unable to double and doesn't oneshot, which doesn't happen every time
That's if we don't talk about armors which are the most common units in the meta.
I would rate Nino much higher than her from the fact that, with neutral IVs and without merges, she can tank physical hits decently, that is even better if you get her without - hp or - def and get her to +10, same as what I've done, and she can even tank some reds

Just for you, I looked up which Tier Florina is in. She is Tier 8, the lowest, and let me tell you, she solo'd so many GHB and Arena Runs (including all armored teams with Hector and/or M!Grima) for me.
What I want to say is: The Tier list just tells you what character is best with lowest possible investment (normally vanilla skill set) for Arena + highest BST + more often used in Arena
So it doesn't really matter for me, I use the units I like, I see that it works and I don't care about the rest.

Because it's based on Arena, which is honestly stupid.

Tier lists as a whole are dumb.

Because the tier list is just someone's opinion and you can have a different opinion that's how opinions work.