I waited for Dogwood. I'm not a big fan of her (she was even my least favorite 6* on Nutaku a long time ago) but she has some unique assets. Let's go! (with Paper Only tag)

Stats:
HP: She has average HP with 20,186. That's not bad but not good. But, due to her game style, she don't really need good stats.
ATK: She is in the top girls here. And that's good because it works well with her abilities.
DEF: Same as ATK. She has a good DEF stats but she don't really need it after all.

Skill
3.8x damage to 2 enemies, 34% skill activation.
It's my least favorite skill type (or should I say, the only one I don't like at all and I avoid as much as possible) so, I can't say it's a good point for her. Damage to 2 enemies is too... not effective. Damages are too low for a single target (like big lonely bosses) and can't hit everyone in pests groups (unless it's a group of 2 pests but that's a bit rare).
But, it's a not that bad ability on Aquashadow missions since some of them has groups of 2 bosses.

Abilities
And that's where and why she shines. A lot. Like the sun. I don't know where I can start. I will just start with the easiest ability I guess.

x1.2 skill rate for all
Same like every girls with that ability. It's good. Very common but always apreciated. For her and above all for her team mates.

+70% Solar Blast damages
SB is too underrated. Especially now with the 300% gauge. The only flaw of this game style is the need of a full 6* team to be efficient. You can't use 5* as placeholder or you will loose too much power unlest Crit team or Counter Team.
I don't know how it works exactly but SB damages is not an addition of all SB damages multipliers. Two +70% SB damages don't give you +140% but more. That's mean, +70% will give +70% if she is alone (and that's not that awesome) but a lot more if you use more and more SB girls. And that' how you reach insane amount of damages.
(I tried with my 5*. I should reach +100% with 3 +20%, one +15% and one +25% but it give me +148%).
Based on my test it seems it's: current SB bonus + xx% (bonus given by the girl) + 0.xx * current SB bonus.
With bit more maths (please stay here!) on my example we have:
We start with a +0% SB bonus
1st girl (+20% SB):
0% + 20% + 0.0 * 20% = +20% SB damages
2nd girl (+20% SB):
20% + 20% + 0.20 * 20% = +44% SB damages
3rd girl (+20% SB):
44% + 20% + 0.20 * 44% = +72.8% SB damages
4th girl (+15% SB):
72.8% + 15% +0.15 * 72.8% = +98.72% SB damages
5th girl (+25% SB):
98.72% + 25% + 0.25 * 98.72 = +148.4% SB damages.
And that's how we reach our +148% insead of the +100% expected. I hope I'm clear with how SB seems to be calculated. Because this is why SB team are so powerful.

Now, back to our dear Dogwood and her Solar Blast dream team. If every girl bring a +70% SB damages we will have a little +2314% SB damages if my formula is right and if there is no SB damages cap. A full 6* SB team gives you a bit more than 23 times more damages than a single 100% blast. And that's a lot of damages.

+25% ATK each 100% SB used
That's sound not good the first time but we are in a SB team. It's easy to reach 300% SB at the start of the mission. Above that, you don't even need to use all the SB gauge fillers in your SB team. You can put some of them in others teams (even if thoses teams will be a bit weaker) and pick all the bests girls for your SB team.
That's said, it will just give you +75% ATK for the whole team at the start of the fight. Just enough to finish the bosses if SB don't burned their bones.

Start with 100% filled gauge
It's just twice the highest SB filling for a 6*. Just with one Dogwood, you have 1/3 for the needed gauge to get her highest ATK boost and a broken ATK. It's the best SB filling of the whole game. That's awesome. Nothing more to say about that.

Team Build
Maybe her worst default. she is a Solar Blast girls, she remains to the solar Blast family and she will never leave it. SB girls alones are just meh girls. They will be OP only when they work together. And that's also why a SB team is harder to build. You must use the bests girls to reach the best build. Unless the other styles where you have a lot of possible builds, SB is more brainless. Get as much SB boost possible + Dogwood, click the death button and wait until the end.

Conclusion
SB is underrated, Dogwood is underrated. By herself she is not that strong unless some owerknown superstars but with the right friends she can be more murderous than every Crit team (almost).
Her abilities are perfect and she became the symbol of Solar Blast (at least for me) like Saffron is the Symbol of Counter.

Final verdict:
In almost every Final Verdict I say I put girls on S tier onyl if they are able to do all by herselves and carry their teams to victory but that time, even if Dogwood can't do that, I will give a her S Tier anyway.
It's not the same S Tier than Kerria or Saffron. If we rate her with the same criteria, she is not even B Tier. But She deserves a S Tier for two reasons. First, Solar Blast is extremely powerful if you useit correctly. And Dogwood is the best SB user, far over all the others.
Second, Dogwood is THE best Solar Blast girl and the only one with 100% gauge filled ability. She is THE must have for EVERY Solar Blast team just like Saffron is the must have for every Counter Team. You can't build a serious Solar Blast team without Dogwood. That's all. And I have no waifu feeling about Dogwood.