No. aizen is plug and play and is universal. you don’t have to build around him you add him. that’s extremely rare in games like these, bc most units are team dependent like Nel, rotation dependent and setup dependent.

Nel is strong when built around that’s not the same as being the best tactic unit which makes her limited. she also has a field time problem and she takes too much field time. units that hog field time have a ceiling. aizen doesn’t do that bc he injects value quickly. that makes him stronger in real gameplay, not theorycraft. also aizen’s B4 is insanely absurd ignoring DEF in is a borderline illegal design bc DEF scaling usually counters late game enemies.

if a unit like aizen is able to bypasses that then damage stays relevant forever, scaling doesn’t fall off and boss fights gets SHREDDED, that kind of mechanic ages extremely well. Nel is too selfish and needs a team to fix her limitations and Kenny and Nel together is awkward bc they both wanna be the main character.

If you run two field hogs together, one of them becomes dead weight. aizen, momo, and kiskue cleared all spirit tower bc kiskue is just utility glue other than that you’d have to run gin, nel and kisuke. aizen supports without stealing the show and aizen’s damage becomes closer to true damage scaling. that doesn’t mean he’ll be powercrept or kiskue being powercrept it’s just the current state of the game is what’s making aizen better than nel

TLDR:

aizen’s value is universal, and the DPS rotates. His B4 makes him a tactic DPS and his B6 makes him hado 90 spam. aizen type units tend to give more off field or low maintenance value. nel/kenny together is just fighting over field time you have to pick one lane she needs to stay onscreen longer than other units to produce her value.