AnotherGuy
Hero
I sympathise - not an easy mess to deal with.I love the player. We have been friends for literal decades. He brings creativity to the game.
But -- with that creativity he brings all kinds of problems. First of all, due to personal issues he randomly doesn't show up (we play VTT) but even worse when he doesn't the game is better.
He is slow with the VTT and always must build the most complex character possible so it's always a chore when his turn comes up.
It's so hard. Ugh.
Tell him his absences are not fair on you (as DM) and on the other players.
And explain to him the difficulty you have when he plays - time is precious and that he unnecessarily complicates, and delays matters. Perhaps as a suggestion run a less complex system RPG with him and the others on the side if your time permits.