Awoken Tachibana Ginchiyo

Not all leaders are created equal. This leader skill is still easy to fulfill, and she has an EXCELLENT active that activates her.

Indeed, with Ult Ilmina's 4.5x Atk on matching Fire/Light ONLY,
Tachibana's 5x Atk on matching Fr/Wt/Wd/Lt is indeed underwhelming.

Note: Both of them have 25% damage reduction upon matching the above colours.

I think the other issue is that Tachibana most likely won't get all that much stronger since she skipped straight to Awoken ult (that just leaves a reincarnated ult).

Illmina doesn't have a super ult or an Awoken ult (yet). She also has higher potential for buffs (and future ult power) since Heroine REM rolls are considered to be GFE's by Gungho.

Eh, Gungho can go back and give them regular Ults anytime. Them skipping straight to Awoken form is basically just a new twist on the Leader/Sub split ults dynamic that past cards have received. Just in this case, the LS stays the same and we're instead forced to choose between a better active for their LS(R/B/G LS that is) or additional awoken skills as subs.

Also, haha, no. I don't trust Gungho to give old special REM cards meaningful buffs anymore after literally every Heroine except Ilmina got dumped on and Academy Sakuya got literally nothing. Face it, they're just going to introduce some new 8* chase card instead.

You don't have all the required colors on your team.

Are you sure your team has wood monster?

You have to "attack with" all colors, not just match all colors. So your team needs to have all colors in either the primary or secondary attack slot.