|Tiki, Beachside Scion enters as a powerful flying option for both mixed teams and flier teams.
With naturally fairly high speed, +Spd is a great boon choice for Tiki, as it allows her to bolster her mixed phase by allowing her to player phase slower targets and not get doubled by enemy targets. However, other boons such as +Atk and +Def can also function well. For banes, either -HP or -Res are best, however keep in mind that -Res is a superbane.
Summer's Breath allows Tiki access to Steady Breath, which flier units generally cannot have access to. This bolsters her counter attacks by having her specials proc faster.
Reposition is a strong movement assist, especially for fliers who have much greater movement flexibility.
Glimmer gives Tiki very strong burst potential on enemy phase, as she is immediately able to fire it off after getting hit once. In addition, if she initiates on an enemy she can get it off on the second hit.
Distant Counter is her strongest A skill, allowing her to counterattack mages at any distance, while using the lower defensive stat from Summer's Breath to easily take them down.
Quick Riposte 3 allows Tiki to effectively fight faster enemies she can avoid getting doubled by by letting them initiate on her if they don't get defeated in one hit by Glimmer
Guidance 3 provides Tiki a lot of support options on a mixed team, allowing her to efficiently move allies around without needing Reposition.
If Tiki is being run in a Flier Emblem team, Hone Fliers or another Flier boost skill is very advantageous.
If Tiki is being run on a dragon team, Hone Dragons or another Dragon boost skill is very advantageous.
Alterantely, any Hone, Tactic, Spur, or Drive skill works on her depending on your team composition.
As for Tiki's Seal, Close Def 3 is generally very useful for her enemy phase, or Guidance 3 as well.