I'll repost what I posted two pages back about tanky unit suggestions so you can get an idea.
As mentioned already, you can't use Wary Fighter unless you are an armoured unit.
-------+
Chrom
Falchion
-
Sol
Armoured Blow
Quick Riposte
Threaten Attack
The idea is to make him tanky and reduce damage taken for when he attacks or takes damage.
Since he is pretty slow, Quick Riposte would be helpful to counter and trigger Sol.
Having him self heal from Falchion and Sol would help trigger Quick Riposte again.
----
Seliph
Tyrfing
Rally Speed
Pavise
Armoured Blow
Brash Assault
Threaten Attack
Similar idea to the above, mentioning it because I have a 5* Seliph.
Thanks for the ideas.
Would you choose Armored Blow over Defense? Since you're trying to make the unit tanky, I was thinking Defense would be better since Armored Blow only works when you're initiating attacks yourself. If you were putting your tank up front to lure someone in, Quick Riposte would help you take the attack and fight back, but Armored Blow would only help you if you need to go in and finish off your attacker, which I don't really see happening.
Say on your turn, you place either of these units, at max health, at an enemy's max range to lure him in. On that person's turn, they go in on you, attack you and activate Quick Riposte. So you take one hit and deal two hits back. If your attacker is still alive, you can then attack with Armored Blow on your turn, presumably to finish him off. That's three attacks from you. In this scenario, Armored Blow would only help you if the enemy unit survives three hits from you and attacks back, which I think is unlikely because most units can probably kill another unit in three hits unless they are at a type disadvantage.
On the other hand, Armored Blow would help you play more aggressively I suppose. You could attack on your turn to activate Armored Blow, but then the enemy unit would counterattack and possibly bring your health below the threshold for Quick Riposte, so you might not get the bonus counterattack on the enemy turn. Armored Blow would help against that of course, but I think the better course of action for a tanky unit is to lure somoene in and let them take the first move so that you can guarantee that first Quick Riposte. In which case, Defense might have a better overall effect than Armored Blow.
Those are just my thoughts though. I could be wrong.