1)
What is the meaning of "Ish Chermi"?
1.
Rashi: The man of My war (who fights against me). It is an expression of Cheirum. This applies to war - "Al Edom Tered v'Al Am Chermi" (Yeshayah 34:5).
2.
Rashi citing Yerushalmi Sanhedrin 11:5: How many Charamim (traps) I set for him until he came to your hand!
3.
Radak citing Targum Yonasan: He was liable [to Me] to be killed. This is like "Charov v'Hacharem" (Yirmeyah 50:21), "Zove'ach la'Elohim Yacharam" (Shemos 22:19)
2)
Why does it say "mi'Yad"?
1.
Radak: This is like "mi'Yadecha".