Technically speaking, when thinking of what weapons to give Mika in Genshin Impact, you can give him literally anything you want. This is because his main utility comes from his Elemental Skill’s Attack Speed boost. And since that is something you can increase via upgrading his Talents, his natural stats don’t matter. However, you can give Mika weapons that enhance his ability to act as a healer on your team.
Mika’s healing through his Elemental Burst scales off of his Max HP. So weapons that increase that will allow him to heal more per Normal Attack. However, his Burst is a little expensive for how much Energy he generates, which means Energy Recharge weapons are also useful. So these are the two stats that you want to keep in mind when it comes to building Mika. Some weapons you can consider are:
Black Tassel is an incredibly cheap and useful option because its main stat increases his Max HP. Other weapons that boost that are ones like Staff of Homa, which should really belong with your DPS Polearm characters. Though this will lessen Mika’s offensive capabilities, he’s not really going to be the attacker on your team anyway. On the bright side, since Black Tassel gives a 40% damage bonus against Slimes, Mika can be your designated Slime Slayer.
Prototype Starglitter is yet another good F2P option since you can craft it in-game Its main stat is Energy Recharge and it provides almost 50% if you max out its level. This will help to keep Mika’s Burst available off of his cooldown. He’s honestly not the most reliable healer but being able to spam it whenever possible can make up for mistakes or a more aggressive play style. Prototype Starglitter’s passive increases Normal and Charged Attack DMG by 8% after using an Elemental Skill. Since Mika won’t really use that, this Polearm is a stat stick for him.
Like Black Tassel and Prototype Starglitter before it, The Catch is a good F2P Polearm that you can get through fishing. It offers the same Energy Recharge boost as Prototype Starglitter. However, its passive focuses on Elemental Burst DMG rather than Normal and Charged Attacks. It increases his Elemental Burst DMG by 16% and Crit Rate by 6%. Like t he Prototype Starglitter, it’s a stat stick for his Energy Recharge.
Like the previous two weapons, Favonius Lance’s main stat is Energy Recharge, though it’s significantly lower. However, Favonius Lance’s real utility comes from its skill. When you land a Crit on an enemy, there’s a chance of generating 6 Energy for the character. At R5, it’s a 100% chance. Presently, Mika works best with attackers like Eula or Kaeya; you could also run him with a character who has better Cryo application to take advantage of Superconduct. In any case, there’s a high chance that you’ll have two Cryo characters in your party (including Mika), which means you can take advantage of Cryo Resonance.
The catch with Favonius Lance is that there are a large number of characters who would want to utilize it. Yun Jin, for example, is a character who would appreciate having Favonius Lance. Unlike Prototype Starglitter and The Catch, it’s also only available in the gacha. If you have Favonius Lance, then Mika should use it. Otherwise, you can consider the F2P options.
Genshin Impact is readily available on the PS4, PS5, Windows PC, and mobile devices. Mika is a 4-star which means he’s always in the gacha.