Should be a lock for Sen if they wanna replace zellsis and bang (which they should)
Great vibes, but different from zellsis', he's at his best on smokes and showed way more confidence than bang, and in theory he can play recon when Sen wants to play dou le duelist with n4rrate.
There are a lot of possibilities to replace zellsis, unfortunately no one is as experienced as he is but Seven would be my first pick and Nismo the second possibility. Both have very good agent pools, can play flash init and sentinel and are a CLEAR upgrade in firepower, Nismo is also a very vocal player which johnqt needs imo. I would also consider chloric but he might want to be the proper IGL somewhere else.
Edit: chloric is actually my first choice I always forget how insane his agent pool and firepower is on top of being an igl
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