It';s fairly self-explanatory. I just wanted to make a Lukas with stupid amounts of defense (that is semi-affordable). Also, you will get crazier stats with all ten merges and dragonflowers.

Obviously, you have to start with Def boon. You could go with either a Spd or Res bane, but I think Res is the least salvageable.

The Daybreak Lance is probably a more logical option, as it is already in his kit and boosts both Atk and Def, but again, I'm just having fun with his Def. So, Vanguard+ with Def it is. (plus I had a 5 star Thea lying around)

Reposition because, eh, why not? You can use other skills like Draw Back or Pivot, but not skills like Smite or Shove, you'll see why soon.

Bonfire or Ignis because, whoop-dee-doo, defense! I chose Bonfire just because it procs quicker.

Steady Stance 3 because, say it with me now... defense!!! You can use Steady Stance 4 if it is available to you, but 3 is way more affordable.

Atk/Def Link 3 provides Lukas and another unit with Def! ...and Atk, but mainly Def!! Honestly, I find Quick Reposte 3 to be more useful here, but I am taking Lukas's Def to the max, so Atk/Def Link it is!

Odd or Even Def Wave works, I just had Odd immediately available at the time. Again, Def!!!

I chose to go with double Steady Stance 3 because... well, why not have a little craziness in your life? Really, you can do a lot with the seal slot: Def 3 for pure defense, Atk/Def Bond couples well with most position-based support skills (sorry Smite and Shove), Armored Blow works so you have extra defense for both phases of combat, Even/Odd Wave Def skills for more doubling up, Close Def 3 it you want to patch up his Res a little, the options are endless!

Well, there you go, a Lukas with crazy Def. Worst case scenario, he will have his base 41 Def, and in best case scenario, he will have the insanity of 76 Def! And that is without merges and dragonflowers, which would make the number even more stupid!

And lastly, if you were to apply these skills to Picnic Lukas, who has even more base Def, you could get a max of 81 Def!!! Again, without merges or dragonflowers!

Have fun with a Lukas that is extremely good at his job, but can't do much else.