The effectiveness of the mimic is largely dependent on your base build (AI starts making dumb choices for casters, base Unga mimics are usually the best) and if you are doing the dumpling trick or not (empty out item list and leave only the dumpling there and the mimic will periodically heal itself). Poopman and Tiche are still solid, often superior, choices. Nephili Louix Puppet is also really good, at least early in the expansion when fighting stuff that is weak to lightning.
Having beaten it twice now (coop as a caster, solo as Unga Finger Shield/bleed spear counterpoke), I feel the Radahn encounter is still way to overtuned and requires specific builds (or Asian twitch reflexes) to pull off. The ridiculously long wombo combos full of chip damage need to be dialed back a bit and the size of the collateral AEs in phase two needs to be reduced so he can't just sperg off a full minute of bullshit where you have to block/dodge with no response only to get chipped down. It is way skewed towards using the Finger Shield to beat it. Ranged builds basically are forced to cheese it or get a cooperator set up to tank the fight. And any setup revolving around smaller fast weapons is just completely fucked with his hitboxes and attack routines. And for fucks sakes get rid of the whole "you just zoned into the arena, let me unload a long chain of bullshit on you" aspect of this and many other boss fights.
The summon is not a trap, really. In fact if you want Albrect's gear you need to bring him into the fight. Having two summons gives you windows to heal and regroup. But it also means you have to be putting out the damage in those windows, which pretty much means you are going to have to roll in bleed (and maybe frost) to get the job done. And your weapon is going to need a fast R1 with enough reach to apply hits in the very small windows this boss gives you, while jumping around all over. This further narrows the builds, but at least you are likely using something from the DLC for a change as the best option.
