Design for consuming list items for a state machine like structure

Question

I'm trying to improve this document parser and there is one main loop that goes over all of the main elements (let's call them Nodes). Each step (Step) can either Consume or Ignore the Node that it is passed. A Step can also be greedy and consume more than the single Node than was passed to it. A Step could restrict its transition to other states like a state machine. I can't remove Node from the list of nodes as that would get me into collection modified while enumerating problems and it would be difficult to accelerate the main loop

What design would work well for this?

Here is something I have been considering to implement.

class Node { ... }
class Step 
{
    void Handle(NodeContext);
    ... 
}
class NodeContext
{
     Node Node { get; }
     void Ignore();
     void Consume();
}