Cast 1/encounter:

Misty Step — Range: 6. Teleport instantly within range. Reaction: When attacked, Defend for free and teleport after damage is dealt.

OR:

Frost Shield — Tier 1, 1 Action, Self Reaction: When attacked, Gain 2×KEY temp HP and Defend for free. The ice melts and these temp HP are lost at the start of your next turn.