What is his 2nd MA?

HP upper limit +10%, no blasting zone casting, attack +100. Same as Gil; you need him at lvl 80 to unlock the 2nd ability. However, he still lacks a Limit Burst.

Limit Burst took too much AP, spamming blasting zone & rough divide with a good defense unit is op

It's not true. Many Limit Bursts have additional bonus effects that greatly scales the favor of the battle towards the user (buffs). He lacks this, but kind of makes up for it with his second master ability.

I like the 2nd MA.

for some units yeah, limit bursts like med cosmo plune or ayaka healing is dope. but for thancred, he's like ramza, limit burst will be useful in certain situations only

limit breaks are key to high end play though. if you want to go far in raids a good limit break would definite make him better. the 2nd master ability doesnt make up for a lack of limit break cause gilgamesh is 2X cost AND HAS a limitbreak and it slows which if you stack with steal time youll be chaining for days, especially with the slash resist down.

so compared to ruin sterne and gilgamesh thancred truly does pale in comparison. sure he has better stats than a regular UR but for double cost and no limit break?

These are not even the same kind of characters. Gil is a mostly squishy support at this point. Ruin Sterne is a damage-focused bruiser.

Thancred is a bruiser as well, with high HP and a resist bubble to help with tankiness.

Earlier arguments about raids and slow mechanics are kind of irrelevant imo. Do you like light units? Do you like this character? Is there room in your team? Done.