The way I see it is the Eradica gives you a reason to bring light frigates and corvettes into even late-game fights. Disciple vessels can be useful with their steal antimatter ability, and once they die they'll be feeding your Eradica with bonus damage. Not to mention that if you've got a level 6+ Discordia Battleship around, each one of them that dies will also inflict direct damage to enemy ships.
I'm thinking of bringing at least a dozen disciple vessels or corvettes into every fight just to have them used as cannon fodder to feed the Eradica's damage.
This all stacks up with the first ability to sacrifice ships for hull and sheild regeneration. You could sacrifice your disciple vessels for slight health boost, while also dealing damage to the enemy thanks to the Discordia, and boosting your own Titan's damage output all in one.
Then there's Return of the Fallen, as mentionned in the post above, which even grants some of your ships the chance to return after the fight.
This being said, I'm fine with the three first abilities. Advent always seemed to have strong fleet compositions to me with diverse ships and capitals, it fits their playstyle.
The final ability, however, annoys me a little. Having my Titan die for it to activate seems harsh. Especially since I don't intend to let my Titan die, ever, unless I've got more income than I could ever hope to spend, and know I can hold off the enemy until it's rebuilt.
I do have a theory, however, which I have not yet tested: since all ability cooldowns are reduced while invulnerable, and antimatter regen is boosted by 500%, could you not simply use this to sacrifice your ships to regenerate the Titan's hulls and shields so when it stops being invulnerable, it's not dead anymore?
Now, for the Coronata. Let's just say I sent it to a pirate base and it took five tries before it shot down all the pirate ships and it nearly died every time, whereas every other Titan so far has done so in one, maybe two tries.
I do like Unity Mass though.
