output – Transactions with NULL handle inputs

I used to be studying this from the Bitcoin wiki (https://en.bitcoin.it/wiki/From_address). I perceive the idea of UTXOs and that any enter to a transaction is an output from a earlier transaction. I even have a tough understanding of how ScriptSig and ScriptPubKey work together. The article mentions “superior transactions will in all probability defeat most block explorers” and provides examples of some transactions one in every of them being:

54fabd73f1d20c980a0686bf0035078e07f69c58437e4d586fb29aa0bee9814f

When this transaction in say blockchain.com the enter is marked as “unknown” and when wanting on the JSON for the transaction the enter handle is “null”

  "inputs": [
    {
      "coinbase": false,
      "txid": "a60143eb3f8d3cd1f42cca874f35736186d67c488efd3c1b7214bbd74b310e0c",
      "output": 0,
      "sigscript": "483045022100d92e4b61452d91a473a43cde4b469a472467c0ba0cbd5ebba0834e4f4762810402204802b76b7783db57ac1f61d2992799810e173e91055938750815b6d8a675902e014f",
      "sequence": 4294967295,
      "pkscript": "76009f69905160a56b210378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71ad6c",
      "value": 9000000,
      "address": null,
      "witness": []
    }
  ],

I then seemed on the enter TXID a60143eb3f8d3cd1f42cca874f35736186d67c488efd3c1b7214bbd74b310e0c and the output handle can be “null”

  "outputs": [
    {
      "address": null,
      "pkscript": "76009f69905160a56b210378d430274f8c5ec1321338151e9f27f4c676a008bdf8638d07c0b6be9ab35c71ad6c",
      "value": 9000000,
      "spent": true,
      "spender": {
        "txid": "54fabd73f1d20c980a0686bf0035078e07f69c58437e4d586fb29aa0bee9814f",
        "input": 0
      }
    }
  ]

Can somebody clarify for me what’s going on right here? And the way one goes about creating these “superior transactions” that apparently defeat block explorers that the article mentions (as in what makes them particular to interrupt block explorers?)

I’ve seen the query at Can PUSHDATA/OP_RETURN be used to interrupt a path of transactions completely? and the reply speaking in regards to the “nonstandard” vout kind however I do not perceive what this implies.

EDIT: I’ve seen “null” addresses within the context of OP_RETURN as outputs however my understanding is that these cannot ever be spent so I do not perceive how they’re used as inputs.