I noticed that, given the current iteration of rules, only Phantoms are currently able to "tank" for their party. Of course this is inherent given role as party guardian but I think tanking should be built in to the basic rules rather than being an ability unique to the Phantom Tager.

The reason for this is that most tabletop RPG, with the exception of D&D 4th Ed., do not make the use of spatial maps mandatory in resolving combat. This has the effect of speeding up play but simultaneously negating questions of positioning, line of sight and obstruction which are the very core of defensive strategy. Regardless of any defensive formation or posturing relative to their allies characters stand and die alone barring GM interference when subjected to an attack as they can still be easily singled out in narrative combat since there is no hard point of reference for launching the attack or tracking positioning.

To this end I'd just like to suggest that V2 adopt something akin to Exalted 2nd Edition's Defend Other and Blockade Movement actions into its basic combat system. This would allow defensive tactics to figure in more prominently into the game without further bogging it down or needing a cumbersome combat grid. 

Defend Other essentially had a character designate another as a person he is protecting for the duration of a turn. If that person is subject to an attack the character can block for that person and, in case of failure, opt to take the hit if he fails to completely defend against the attack. If the attack gets through the defender's efforts the person protected defends accordingly. Blockade Movement on the other allowed a character to designate an enemy whom he would hinder. If that enemy moves a certain way he can move to block his movement, engaging in an opposed roll to prevent him from getting anywhere. 

By way of illustration think of a line of riot cops; the ones with shields up front would be using a combination of Blockade Movement and Defend Other actions to protect the cops behind them who are launching tear gas and rubber bullets at an onrushing mob who'd also be hurling bottles and other projectiles. Absent these rules the mob would be able to directly assault the cops at the back, either bypassing them entirely and just accepting opportunity attacks or making range attacks against them, with impunity as if the shiedwall wasn't there.

I think adding these to the basic system would encourage team play and encourage tactical thinking.

As to the Martyr ability I think instead of making it a distinct action maybe it could instead be a buff to the Defend Other action? In a way simulating the Phantom's predisposition to defending his packmates. Like a die and armor bonus when interposing yourself against an attack.