BLU tier2 merits

[Subzero]

Ive put 1 in each besides Assimilation. so 3/6, just looking for others people advice on what to put the last 3 in, I know ill leave Diffusion at lvl1. WAs thinking Convergance2 Enchainment3 Diffusion1. I know its just opion and all..but maybe 1 of the other is better to have maxed lvl3.

[LD]

Despite the lack-luster enhancement per upgrade, Assimilation is still probably the most practical.
Convergence gives an impressive bonus, but it's only worthwhile if you're using nukes or breaths often.
As things stand, you don't want to put more than one merit into Diffusion (I wouldn't even put in one...)
Enchainment, that's up to you, can't really be for it or against it enough to make a statement.

[VZX]

Planning on 3 enchainments for sure. (Can be nice for F Rip and accuracy of Disseverment)
1 diffusion just to make it available
the other 2 points left either all go to convergence or split up between convergence and assimilation

[Teorem]

Enchainment - 3
Assimilation - 2
Convergence - 1

I do a lot of soloing with BLU (194 merits and counting) so I chose mine to augment that. The difference between 0TP and 30TP through Enchainment (even 20TP, if you only upgrade it twice) is noticeable, especially when you are self-skillchaining. Having 47 set points through Assimilation allows me to set my damage spells, Stoneskin (Metallic Body), Auto-Refresh, Conserve MP, and two levels of Clear Mind. I put a level into Convergence for its accuracy bonus, although I still get a half-resist from things like Magic Hammer on occasion.

I started off with a level in Diffusion, but after unlocking it and finding absolutely no practical use to it over the course of the next two weeks, I dropped it. I'm more likely to be a BLM rather than a BLU giving a BLM party a 30-second Magic Attack Bonus from Memento Mori, and the 20-minute reuse timer is really laughable...even if you merit it down completely to 15 minutes.

[Tonko]

Above poster has it pretty spot on. One Convergance for Magic Hammer bonus fun every 10 minutes when soloing Imps, and clutch utility in versatility situations is quite nice. Assimilation is more usefull than people give it credit for. Sure, 2 or more points per upgrade would've been great, but more stat bonuses & more spells set is always a good thing. And 2 Enchainment for Damage bonuses on Frip & Cannonball, and accurecy for your Distortion Disseverments makes things happier overall.