Heroic multi Melta idea

I have an interesting idea brothers (or maybe bad i don't know) which is a heroic multi melta for heavy. the name of the multi Melta is The Promethean Dirge (it saw a lot of battles..yet it works as the best one of them.) Appearance old and beat up with a dark metal casing held together by heavy rivets and reinforced plating and The side is embossed with beat up Aquila, marking its allegiance to the Imperium. special power called Bastion's perseverance. : it replaces heavy defense from balance to block and if he hits with a fully block stacks it will restore 3 ammo and one armor. same as the relic alpha one but has 26 ammo instead of 30 but plus 3 on range