Vantage 4 - A Way Out

A little while ago I proposed a [Tier 4 version of the Defiant skills](https://www.reddit.com/r/FireEmblemHeroes/comments/1ambogd/defiant_t4_skill_idea/). Today, I'd like to propose a Vantage 4 option to help combat pre-combat damage. Let me know what you think; is it too good/not good enough/needs tuning?

**Vantage 4**

*Inflicts Spd-4 on foe during combat. If unit's HP ≤ 99% and foe initiates combat, unit can counterattack before foe's first attack and if unit's HP ≤ 75% unit can make a follow-up attack before foe can counterattack. Reduces effects that "deals damage to foe as combat begins" by 50% (min. 7) and if unit takes ≥ 8 damage as combat begins, unit gains: "Neutralizes effects that disable skills that change attack priority."*