Deceiver when I conquer or hold from Leblanc can it be used on a unit on base?

No, you cannot. The Reflection token and its copy effect are both restricted to the battlefield you conquered or held.

The Deceiver ability reads: "play a ready Reflection unit token there. Then do this: It becomes a copy of another unit there." Both uses of "there" refer to the battlefield where the conquer or hold occurred (confirmed in FAQ #11091). The token is placed at that battlefield, and the copy effect can only target another unit at that same battlefield — not a unit at your base or anywhere else.

If there are no other units at that battlefield when the copy resolves, the token simply remains a 0 [M] Reflection (and gains Temporary).