Water Luer (Luer)

I hear folks refer to Luer as "the poor man's Galleon" a lot and they can be used similarly, however something to point out: Luer's S3 always lands as a crushing hit, regardless of attribute, it drops their ATK bars by 50% and applies a DEF break. His S2 attacks multiple times (albeit random) and slows for 2T. Between these 2 skills you can keep your enemy "locked down" and gain serious turn advantage over them- especially if you put him on Despair. I find Galleon more effective in the Arena (since your attack buff and debuff are on 1 mon with 1 skill and slowing them isn't as important, since I'm going to kill them) but Luer gets the edge in TOA- where the ability to affect a critter regardless of attribute is far more important- and NOT slowing them can cost you the run. So simple answer: build both. 

In my oppinion, Luer is a game ghanger in early-mid game, but his utility drops in late game. The AoE 50% ATB reduction is simply too OP in early PvP battles. Just give him your fastest Swift set and an accuracy rune in position 6 and enjoy...

Later, in mid game, Chloe will be his only real problem, specially if the enemy epikion is faster than him. Otherwise his S3 will still change the tide of the battle.

In late game, units like faster Woosas, Tianas, and the use of Will runes or high Resistance teams will really drop the utility of Luer´s third skill unless you can get a good syncroniced team with an AoE stripper right before him.

In my oppinion, Luer is not as useful as Galleon only because Galleon can make profit of each one of his skills, but Luer´s S1 and S2 aren´t any good as I see them. Concerning this, the long cooldown time of Luer´s S3 is another important thing to think in.

So I would say that if you pull this unit in early game you´re pretty lucky cause you will have plenty of game time to use him both in PvP and PvE, but unless you have a specific team for him, he will probably lose utility in late game battles.

I haven't personally built a Luer, but what I have seen about him on other sites suggest that he is more intended for bruiser comps that do damage based on HP. They are generally slower, so the ATB reduction from Luer helps them get their turns in, and they don't need the atk buff because their damage is coming from HP. I think he doesn't hold much ground in later game arena because the rush hours get to be more about speed clearing to get to the top, and no one wants to be using a slow, bruiser comp when they are trying to finish in guardian.

I use him on my troll arena def..  Susano(5* nuker) bastet(5*swift focus) Lapiz(5*/despair rev atk%x3) and this Phantom(no awake and 4*/despair focus spd,hp,acc)..  and really i was surprised how many battles they won the first time, so i  used they since.  

so, i decided to prove it in auto mode. Too much sincro with that team. the enemies don't got any turn. but only early-mid players works. I break to many def full 6* amx lvl even auto mode. the only problem, the slow+will mobs..