We know that units become relatively weaker over time due to powercreep. Why is it ok or not ok for a unit to drop off? How strong should an investment remain, for how long, and why? What difference does it make, if any, whether the unit is top tier, middle of the pack, or lackluster on release?
For example, let’s say a seasonal banner releases when I have 500 orbs and I decide to merge the 4* special. Moreover, since baby banner units tend to be a bit stronger than those on other seasonal banners let’s say it’s someone like Raphael or W.Hilda instead of Y.Lyon. How long should I expect this unit to be effective, and why? How do we define “effective?” Best in that unit class (as in, same weapon and movement type with comparable statline)? One clean cut stronger than an unmerged version of the latest 5* exclusive? Able to win reliably at high ranks of the gamemode where they’re good? Whichever definition you choose, why should the unit be that strong for the length of time you’re proposing, or why is it bad for the game if they drop off faster than that?
Let’s also consider the common case of pulling for a single copy of a 5* exclusive. Suppose I spark one of the new fallen units. How strong should this unit be compared to strength (relative to the meta) at release, 12 months later? 18 months? 24 months? 30 months? Why should it be that way and not stronger or weaker? Why would that be good for the game, or the failure of that condition bad for the game?
Then let’s consider a unit that I might merge or ignore, a demote unit on a permanent pool debut banner. Where should this unit stand compared to their place on debut, 12 months from that time? 18 months? 24 months? 30 months? What does it have to do with the average length of time required to accumulate 11 copies if you ignore the unit at their debut? Why shouldn’t that unit drop off quicker?
What about a grail unit, either a GHB or a TT unit?
Lastly let’s consider the rarer case of merging a 5* exclusive; doesn’t matter that much if it’s permament pool or seasonal or legendary/mythic. If it’s done over, say, 4-8 months (maybe 4 months if you had lots of orbs saved at the debut and then the BHB came at a convenient time for you to finish), how strong should we expect this unit to stand in the meta one year from release? 1.5 years? 2 years? 2.5 years? And why?
I’ll offer some of my own thoughts after the discussion has progressed a bit.