Immunity Shield + Interruption Circles
This is not really difficult to deal with, you MUST however bring a unit with elemental advantage to break the interruption circles. Not being able to doing this will cause a team wipe attack. These circles compared to the other anomaly interceptions are actually very durable, requiring strong water units to break.
Rapture Swarm
In this version of Harvester instead of only spawning mobs when it is knocked down, raptures will continuously spawn over a short period of time in intervals to support the boss. They are not very durable but will be overwhelming and deal heavy damage the longer they are on the screen. Clearing them out as soon as possible is recommended.
Targeted Laser
Every so often the boss will target a single NIKKE in your team from the left or right and sweep across to each subsequent NIKKE, this laser deals heavy damage but can be covered and or shielded. Make sure that if you are using an element weak NIKKE that they are well covered as they take bonus damage.
Other mechanics
Harvester in Anomaly Interception is slightly different from its counterparts in that it does not have breakable legs. Instead, there is a part and core on his head that once broken will knock the boss down. The part is very durable and will take quite a bit of damage to break, so the priority should be on that.
Other attacks that the boss will do is simple attacks from the head that occurs randomly during the fight but constantly rotated. Breakable missiles and other laser attacks that target single NIKKE will occur in this rotation. These attacks differ as in they do not have attack indicators, if an attack does, then it is dangerous in this fight.
Bringing Water units is extremely important in this fight, as it will be to bring mono element teams (as much as it is possible) for every Anomaly interception. Units that excel for this raid like Dorothy or Ludmilla: Winter Owner are exceptional in this raid, but other DPS units that are non-elemental advantage can also work fine, as long as they are not element weak.
Stage 7 example run by Riza without Quency: Escape Queen
Stage 5 example run by Tharsis