Retirement tax questions

But won't you get hit again and again (if you continue to take these withdrawals or RMDs in the coming years)? Or was this a one-time event. Curious myself.
As we age, these RMDs might eventually become substantial - ours already are.
I use the "RMD method" of paying taxes (i.e., avoiding paying quarterlies in retirement). In our case, I take out a bit more than I need to in late December and over-pay taxes a little knowing I'll get most of it back by April.